Improve CLI docs

[tigerros]

• Fixed all the typos (hopefully).
• Improved the bad English. This encompasses grammar, vocabulary, generally awkward phrases, etc. The result is easier to read and understand, and in some cases shorter.
• Made some formatting improvements. This includes making formatting more consistent, but I changed some of it to be better, at least in my opinion.
• General fixes. For example the dioxus-cli crate README points to a non-existent documentation URL. One more URL I recall is the Dioxus logo at the CLI intro page, which leads to nowhere. Removed it because I don't think it's necessary, and no other chapter has it.
• Removed certain unnecessities, the biggest one being the commands documentation. I think this is unnecessary because of the dx --help command. It basically just repeats what dx --help says and it's an extra burden since it needs to be updated every time a command gets added/updated/removed.
• Improved plugin documentation. I added a warning for the reader to ignore all of it, which is ironic, but the fact is that plugins are probably going to change. But by the time I learned that, I already made some changes to the plugin docs. This includes a better guide on how to get started (although still bad since the plugin system is too messy), and general changes like the aforementioned English or formatting.
• And more. I can't list it all, but I didn't do any destructive changes. The content might be reformatted (to be shorter or easier to understand), but the meaning isn't lost.

[ealmloff]

This looks great! I agree that removing command documentation makes sense. The published CLI docs now live at https://github.com/DioxusLabs/docsite/tree/master/docs-src/0.4/en/CLI, not in this repo. See #1408

[tigerros]

The published CLI docs now live at https://github.com/DioxusLabs/docsite/tree/master/docs-src/0.4/en/CLI, not in this repo. See #1408

Really? docs-src/0.4/SUMMARY.md has incorrect paths. It ignores the fact that everything is in the docs-src/0.4/en directory. Does it still work? Snippet from SUMMARY.md:

# Summary

[Introduction](index.md)

File structure:

0.4/
  ...
  SUMMARY.md
  en/
    index.md
    ...

[ealmloff]

Yes it works. We have a custom mdbook parser that knows about the version/language structure: https://github.com/DioxusLabs/include_mdbook

[tigerros]

Okay. I'll make a PR in the docsite repo, but this PR also changes the dioxus-cli crate README, since it also had some issues, and that README is not in the docsite repo. So I think this should be merged, but perhaps without the docs directory.

Edit: docsite PR: DioxusLabs/docsite#111