Resolve #22, #20

[belcar-s]

This pull request resolves #22 and resolves #20.

This is my first substantial contribution to someone else's software, so please be patient and forgive any issues 🙂.

These changes enable the use of the extension in project-less windows:

Except during editing of unsaved documents 🙁:

They also cause tasks defined in deno.jsonc files to be displayed inside the Tasks menu:

I used the strip-json-comments NPM module to parse JSON with comments files, and tried to mimic the way vscode-languageserver-types was imported.

[sgwilym]

Released in v1.0.4!