Merge id fix

[Nynxz]

This pull request introduces a new dynamic node for merging IDs in the UI, updates the documentation with usage examples and screenshots, and bumps the extension version. The main focus is on improving user experience by allowing more flexible node input handling and providing clearer documentation.

UI Node Enhancements:

• Added new EmbeddrMergeIds node (ui/nodes/EmbeddrMergeIds.ts) that dynamically adds or removes string inputs based on user connections, ensuring seamless merging of multiple IDs. The node is registered in the main UI entry point. [1] [2]

Documentation Improvements:

• Expanded README.md with a new "Usage" section, including screenshots for loading/saving images, retrieving from collections, and using the WebUI, to better guide users.

Versioning:

• Bumped the extension version from 1.2.0 to 1.2.1 in pyproject.toml to reflect the new features and improvements.