Improve the "Development" section of README.md

[zeroSal]

I'm trying to contribute to the extension, but I can't run in debug mode the extension as bun build run in the root of the project does not build and package the extension. I think you should improve the "Development" section describing all the developing cycle:

• Setup dev environment (this is already documented)
• Debug the extension in VS Code
• Build the extension to test in a "production" environment

[SanderRonde]

I've updated the docs a bit. It's all actually pretty simple if you have VSCode but I can imagine it's not super easy if you have no prior experience with VSCode extensions so I've written it all out.

[zeroSal]

I've updated the docs a bit. It's all actually pretty simple if you have VSCode but I can imagine it's not super easy if you have no prior experience with VSCode extensions so I've written it all out.

Many thanks ;)