init wiki (#2)

* init the wiki (tutorials, node references)
* add simple nodes: ConvertToAny, ResolutionToDims

wiki/node reference/xy plot/00 - core concepts.md

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+# Node reference / XY Plot: 00 - Core concepts
+
+As a minimum, to use the `XY Plot`, you need to integrate 2 nodes, `XY Plot: Queue` and `XY Plot: Render`: the first one will organize the queue, the second one will render the grid(s).
+
+![standard nodes](./images/nodes.jpg)
+
+They must be connected by the specific `XY plot data` link : that is the way the queue can inform the render node about the current processing state.
+
+What is processed between them (from `dim1 value` / `dim2 value` outputs of `Queue` to `image` input in `Render`) is for you to choose: as such, **the ComfyLab's XY Plot approach is totally process-independent**.
+
+## XY Plot: Queue
+
+As you can see in the screenshot, there is no concept of row / column or X / Y here, as in many other plot / grid implementations:
+
+- instead, we talk about `dim1` and `dim2` (dimensions 1 & 2)
+  - this is intended, to improve performance: but we'll talk about that later
+  - just remember this rule: **for a given `dim1` value, we process all values of `dim2` before switching to the next `dim1` value**
+  - whether `dim1` and `dim2` are rows or columns is configured later, in the `Render` node (`direction` toggle)
+- `dim1` and `dim2` (optional) **take lists as inputs**
+  - in ComfyUI, a LIST is a LIST, but we cannot know if it's a list of strings, numbers, images, ...
+  - so another important rule: **what you send is what you get**
+    - said differently: if you send a list of numbers, you will get number values in output
+    - or one could say: sh\*t in, sh\*t out...
+- for the reason above, the `Queue` node cannot determine what it will get in input, so the type of the outputs is set to `"*"` (Any)
+  - this makes the `dim1 value` and `dim2 value` outputs very flexible, as you can basically connect them anywhere
+  - but it comes at a price: **you must ensure that the data in input correspond to the expected data in output**
+    - for example: if you connect `dim1 value` to the `cfg` input of `KSampler`, you must ensure that the input list is a list of floats. If you send strings, you will obviously get an error when running the workflow
+- one of the main features of the `Queue` node is **auto-queuing**
+  - no need to reset a counter, or manually increase the batch size
+  - **the `Queue` node will take care of that for you**
+  - in fact, you should definitely **not set the batch size to anything else than `1`**
+
+## XY Plot: Render
+
+The `Render` node, in its default configuration is easier to understand:
+
+- it takes an `image` as input, for example the result of the `KSampler` processing
+- <ins>important</ins>: you are not limited to KSampler
+  - in fact **you can do what you want between the `Queue` node and the `Render` one**
+  - it could be loading the image from a folder, doing some image transformations... you decide
+- it has 2 outputs:
+  - `image` is the single image, as received in input
+  - `grid` is the generated grid, when it has received enough images
+    - obviously, you can generate multiple grids, if you configure pagination in the `Queue` node
+
+## dim1 vs dim2, which one should I choose? (or the Performance Question)
+
+As seen above, connecting an input list on either `dim1` or `dim2` doesn't determine if data will be displayed as rows or columns: you can simply switch the `direction` in the `Render` node.
+
+So, what does it change?\
+In the most simple cases, for example if you plot `CFG` vs `seed`, it should not have any visible impact.
+
+But now, imagine a more advanced case: I want to plot a given list of 3 seeds vs a list of 3 checkoints with the default `KSampler` workflow.\
+Let's recall the rule above: **for a given `dim1` value, we process all values of `dim2` before switching to the next `dim1` value**.\
+That means that, if I set the list of seeds in `dim1`, the process will work as follows:
+
+- get seed #1, get checkpoint #1 > <ins>load checkpoint #1</ins> > render image
+- **keep** seed #1, get checkpoint #2 > <ins>load checkpoint #2</ins> > render image
+- **keep** seed #1, get checkpoint #3 > <ins>load checkpoint #3</ins> > render image
+- get seed #2, get checkpoint #1 > <ins>load checkpoint #1</ins> > render image
+- ...
+
+Loading a checkpoint is a costly operation, in terms of performance: we don't want to load a new checkpoint at each and every iteration.\
+So let's switch, connecting the list of checkpoints to `dim1`, and the list of seeds to `dim2`:
+
+- get checkpoint #1, get seed #1 > <ins>load checkpoint #1</ins> > render image
+- **keep** checkpoint #1, get seed #2 > _do not load checkpoint #1_ (it's in memory) > render image
+- **keep** checkpoint #1, get seed #3 > _do not load checkpoint #1_ (it's in memory) > render image
+- ...
+
+By doing so, we optimize the performance as much as possible.\
+So as a general rule: **if you need to vary models (checkpoint, LoRA, ...), ensure these values are connected to `dim1`**.\
+(And if you vary 2 lists of models, obviously choose the slowest as `dim1`).

wiki/node reference/xy plot/01 - queue and render.md

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+# Node reference / XY Plot: 01 - Queue and Render
+
+**Work in Progress**
+
+## Node overview
+
+![standard nodes](./images/nodes.jpg)
+
+### XY Plot: Render
+
+As per the widgets:
+
+- `dim1: header format` and `dim2: header format`
+  - enter here a template string, following the syntax of Python string `format()` method
+  - the `{dim1}` and `{dim2}` placeholders will be replaced by the current dim1 / dim2 value
+  - very handy if you want to prefix the row / column headers, for example:
+    - if you have CFG values in dim1, by default the headers will be `7.5`, `8`, ...
+    - just change the dim1 header format to `CFG: {dim1}` and you will get: `CFG: 7.5`, `CFG: 8`, ...
+  - there are plenty of advanced techniques, but you will probably not use them here
+    - however if you want to learn more, you can check the [`Format` node reference](../format.md)
+- `direction`: whether dim1 values are displayed as rows, or columns

wiki/node reference/xy plot/02 - config nodes.md

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+# Node reference / XY Plot: 02 - Config nodes
+
+**Work in Progress**

wiki/node reference/xy plot/README.md

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+# Node reference / XY Plot
+
+[00 - Core concepts](./00%20-%20core%20concepts.md)