Update built-ins for Open VSX publish

[marcdumais-work]

The built-ins package.json are missing many fields that are
desirable to have so that the extension's page on Open VSX
will be populated correctly.

Fixes #19

How to test:

0. build this repo and obtain the .vsix from the dist folder
1. open Open VSX in Gitpod
2. create a builtins folder at the root
3. use a file manager for your OS and drag-and-drop the generated builtins to the GitPod file navigator, over the builtins folder
4. use the openvsx client to create the vscode namespace:
   $> cli/lib/ovsx create-namespace vscode -r http://localhost:8080 -p super_token
5. use the openvsx client to publish a built-in extension to the (test) registry. e.g.:
   $> cli/lib/ovsx publish -r http://localhost:8080 -p super_token builtins/grunt-1.40.0-prel.vsix
6. Open the web page for the registry (the one on port 3000) and search for the extension you published. Look at the first page and detailed page for the extension.

[marcdumais-work]

Already starting to be better:

Note: Grunt and Git are among the rare built-ins that provide an icon

[akosyakov]

I am fine with it, but we should also make sure that it looks good in the registry by default to. We won't be able to fix all VS Code extensions in such way.

[marcdumais-work]

I have refined a bit:

• take displayName and description from package.nls.json if available there, else fall-back to a sane default for these important fields.
• let Open VSX provide a default icon if missing (most are)
• add a basic README, overriding existing one if present (rare)

[marcdumais-work]

What it looks like now using Open VSX master on Gitpod:

[marcdumais-work]

@akosyakov are you fine with merging this PR? Here is the plan after:

• merge the fix for emmet: include runtime dependencies for emmet #22
• Generate builtins v1.39.1 (without -prel)
• Publish result to public Open VSX

Any objections?

cc: @spoenemann

[spoenemann]

What is Code OSS? VSCodium?

[marcdumais-work]

What is Code OSS? VSCodium?

That's what Microsoft apparently calls what one can build from the vscode GH repo:

https://github.com/microsoft/vscode/wiki/Differences-between-the-repository-and-Visual-Studio-Code#the-code---oss-repository

[marcdumais-work]

i.e. VS Code without the proprietary components and configs

[spoenemann]

Ok, so VSCodium is an example of Code OSS.

👍 ok to merge from my side.

[marcdumais-work]

Ok, so VSCodium is an example of Code OSS.

Yes, or we could say a derivative of it. BTW, they took the decision to still include the MS Marketplace config as part of VSCodium, but I read somewhere they'll be willing to switch when something open is created. So I think they will be a good candidate to use Open VSX once it's compatible with Code OSS-based editors.

[marcdumais-work]

@akosyakov are you fine with merging this PR? Here is the plan after:

• merge the fix for emmet: include runtime dependencies for emmet #22
• Generate builtins v1.39.1 (without -prel)
• Publish result to public Open VSX

Any objections?

cc: @spoenemann

Merging, based on #20 (comment) and #20 (comment)

[marcdumais-work]

Ok all done.