webview-codicons: Move codicons dependency from devDependencies into dependencies

[phil294]

This is the core information I needed from this sample folder: Where do I put the codicons / how are they required? Do I really need to ship the full .ttf file in my .vsix bundle, even though it is clearly already present in all VSCode installations?? The answer to this question is YES, and it would be clearer to see if the dependency were listed in dependencies, which is where they also really should be.

Apart from that, the sample doesn't compile properly when you try to make a demo bundle out of it: Change publisher to something else, run npx vsce package and inspect the resulting vsix file: It's missing the node_modules folder, which further confused me a lot. Not sure why or how to include it. There's also no .vscodeignore file present, because of which unnecessary stuff like the .ts files are also shipped along.

Sure, this sample isn't a full guideline, but it sure would be great if one could actually create a best-practice demo vsix here.

I'll also create an issue out of the above text in a second. Edit: No, I won't, there already is one: #692. This PR seems to fix it:

Fixes #692

Best regards