Add docs

[king-p3nguin]

Before submitting, please check the following:

• Make sure you have tests for the new code and that test passes (run tox)
• format added code by black -l 120 <filename>
• If applicable, add a line to the [unreleased] part of CHANGELOG.md, following keep-a-changelog.

Then, please fill in below:

Context (if applicable):

Description of the change:

• Add docs
• Run CI on schedule

Related issue:

also see that checks (github actions) pass.
If lint check keeps failing, try installing black==22.8.0 as behavior seems to vary across versions.

[king-p3nguin]

@shinich1 I added a tutorial and module references in the document. Since the tutorial covers most of the functionality of graphix-perceval currently implemented, I left the example section blank.