Write "Working with Extensions / Bundling Extension" topic

[octref]

Related: microsoft/vscode-extension-samples#122

• Create a new topic under api/working-with-extensions for https://github.com/Microsoft/vscode-extension-samples/tree/master/webpack-sample
• Explain benefits of bundling
• Together with the sample, illustrate how to bundle extensions using webpack

[DanTup]

Please also include a section for tests (both running from VS Code via launch.json and if much different, running from the command line for CIs), as I was unable to get tests working when I updated my npm scripts to use webpack (see microsoft/vscode-extension-samples#110 (comment)).

[KamasamaK]

Related #2403

[jrieken]

@octref Do you want webpack as separate guide? My initial planning was to put this into api/working-with-extensions/publishing-extension.md so that it is not more prominent/easier to find. My thinking was the the base-publishing guide should prepare you for the webpack-guide

[octref]

I think separate topic (api/working-with-extensions/bundling-extension.md) is better:

• It's on TOC, so even easier to find
• The publishing guide could link to the bundling guide in "Next Steps", you can also put it right after publishing guide in TOC

[jrieken]

fyi - I have pushed a first cut via 1023304

[DanTup]

@jrieken If you're looking for feedback, a section on tests would be appreciated. I couldn't figure out how to make tests work after changing the extension to be packed (specifically, I wasn't sure what the launch.json/packages.json should look like to run them with F5 from VS Code, or from the terminal).