Markup options in a table format

[yudai-nkt]

This PR prints CLI options in a rich table format instead of a plain format we see in terminal. In addition to that, the section name "Options:" is made bold in order to be better aligned with mkdocstrings' heading.

w/o PR:

w/ PR:

(These are fixed in 6f89573) Current implementation has the following restrictions, but I suppose most of the use cases don't fall under these situations.

• If any of the help messages starts with a hyphen, the resulting table would not be what users expect.
• If help messages are written in certain languages (Chinese, Japanese and Thai AFAIK), they might contain unwanted whitespaces. I don't think we should care because this could happen in HTML and Markdown in general and is not a critical problem.

Fix #11.

[yudai-nkt]

I added three more columns (i.e., Type, Required, Default) so that these information becomes more recognizable and descriptive. Now the result looks like this and I suppose the table is easier to grasp at first sight.

EDIT: I changed to use the same table format as mkdocstrings' parameters (example and source) and the Required and Default columns are now merged. Sample image is updated accordingly (the previous version can be previewed here).

w/o PR

w/ PR

[florimondmanca]

@yudai-nkt Thanks so much for putting time into this. I commented on #11 — right now I don't think this particular form of the PR is exactly the way we'd like to go; rather, we should look at adding this in a backwards-compatible way. So I'd like to close this for housekeeping purposes only, but be assured that I fully appreciate this contribution and we can continue discussion on ways to get this in on #11. Thanks!