Poetry: A few documentation issues

[Keats]

• [x] I have searched the issues of this repo and believe that this is not a duplicate.

Issue

Hi!

It seems that there are a few issues in the docs:

• commands are not up to date: cache:clear, list, develop, debug:* are not listed at all in https://poetry.eustace.io/docs/cli/
• links in the sidebar are relative so if you click on any of them, any click on another link other than hashes will be a 404. For example clicking on Commands and then Libraries will try to load https://poetry.eustace.io/docs/cli/libraries/

[jacebrowning]

The 404 on the documentation site means no one can complete the issues checklist that requires us to search the docs.

[yunti]

poetry shell missing in the docs too

poetry self:update and --preview flags etc... aren't listed in the docs commands too

[sdispater]

I fixed the 404 errors in the documentation.

And I agree that the documentation needs an update. I will try to do it before the next 0.12 release.

[AtomBaf]

Hi
I'm adding this typo to this issue (not sure if I need to create a new one since it is very similar and quick to resolve) :
In the https://poetry.eustace.io/docs/configuration/ page, the last link is not good
should be https://poetry.eustace.io/docs/repositories/ but the 'docs' part is missing

Created a pull request: https://github.com/sdispater/poetry/pull/456

Thank you