Dotty internals docs update, dotty knowledge collection system integration

[anatoliykmetyuk]

This PR ports the knowledge from https://github.com/anatoliykmetyuk/dotty-cookbook to the official docs. Also, I've created https://github.com/lampepfl/dotty-knowledge where we can collect new knowledge (and also express intents with respect to e.g. modification of the knowledge base or flagging content as outdated). Also, this PR adds the following badge to this repo:

I did this to further reduce the overhead of knowledge collection so that the means to log your knowledge is highly visible and clear. However, this may create the risk of abuse by non-contributors using "Add Knowledge" feature to log user-side knowledge. I think this risk is acceptable and in line with the overall philosophy of deliberately not going for quality on the knowledge collection stage.

Comments and suggestions are welcome!

[dottybot]

Hello, and thank you for opening this PR! 🎉

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Commit Messages

We want to keep history, but for that to actually be useful we have
some rules on how to format our commit messages (relevant xkcd).

Please stick to these guidelines for commit messages:

1. Separate subject from body with a blank line
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8. Use the body to explain what and why vs. how

adapted from https://chris.beams.io/posts/git-commit

Have an awesome day! ☀️