Update communityNodes.md (#3873)

Added the Ideal Size node

## What type of PR is this? (check all applicable)

- [ ] Refactor
- [X] Feature
- [ ] Bug Fix
- [ ] Optimization
- [ ] Documentation Update
- [ ] Community Node Submission


## Have you discussed this change with the InvokeAI team?
- [ ] Yes
- [X] No, because: It's a community node addition

      
## Have you updated all relevant documentation?
- [X] Yes
- [ ] No


## Description

Added a reference to my community node that calculates the ideal size
for initial latent generation that avoids duplication. This is the logic
that was present in 2.3.5's first pass of high-res optimization.

## Related Tickets & Documents

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- Closes #

## QA Instructions, Screenshots, Recordings

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Please provide steps on how to test changes, any hardware or 
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## Added/updated tests?

- [ ] Yes
- [X] No : This is a documentation change that references my community
node.

## [optional] Are there any post deployment tasks we need to perform?

docs/nodes/communityNodes.md

@@ -42,6 +42,11 @@ The nodes linked below have been developed and contributed by members of the Inv
 
 ![Invoke AI](https://invoke-ai.github.io/InvokeAI/assets/invoke_ai_banner.png)
 
+### Ideal Size
+
+**Description:** This node calculates an ideal image size for a first pass of a multi-pass upscaling. The aim is to avoid duplication that results from choosing a size larger than the model is capable of.
+
+**Node Link:** https://github.com/JPPhoto/ideal-size-node
 
 ## Help
 If you run into any issues with a node, please post in the [InvokeAI Discord](https://discord.gg/ZmtBAhwWhy).