Add feature to Add to an existing Row

[guigro]

Summary

• Add new "Add to existing Row" input event that appends values to existing rows based on a key identifier
• Optimize data fetching to only fetch column A first, then the specific row (instead of fetching all columns A:ZZ)
• Update README with documentation for the new feature

How it works

• The first value is used as a key (ID) to find the row
• If the key exists: values are appended at the end of that row
• If the key doesn't exist: a new row is created with the key + values

Performance optimization

Instead of fetching all columns upfront, the code now:

1. Fetches only column A to find the matching key
2. Fetches only the specific row to determine its length
3. Appends values at the correct position

This reduces data transfer significantly while maintaining full functionality.

[chetbox]

This is neat, thanks so much! I left just a couple of comments for improvements.

[chetbox]

One last tiny thing, could you remove this file? It's not a big deal but we just like to keep our repo so only necesary files are included.

[chetbox]

Thanks so much for this feature @guigro! ⚙️

[chetbox]

This feature has been released in v0.3.0