Tutorial and documentation style upgrade

[shinich1]

Describe the feature you'd like

1. Upgrade the sphinx theme to sphinxawesome_theme and ensure all introduction pages, tutorial, API docs and examples are shown properly. Make sure builds on readthedocs.org pass. Make sure the logo shows up on the top bar of the page, as in the current version (choose appropriate color for logo). the logo file is in docs/logo.
2. Update the tutorial page: incorporate latest version of the code, and make the page easier to follow. Use pattern.draw_graph() visualization tool as appropriate. Incorporate examples (this and this ) into tutorial page, and remove these examples.
3. update the introduction to MBQC and introduction to LC-MBQC pages to incorporate latest version of the code and make them easier to follow. Make sure to mention this paper which includes the general framework of MBQC with LC-decorated graph states, which our idea of pattern-based MBQC with LC is based on.

Additional context
Before preparing PR, please build the updated docs on your fork using readthedocs.org (login with you GitHub account and you should be able to see the forked repo to build; let me know if you have trouble configuring/building).

[Roshan-Thomas]

Hi, I am working on this issue, and I will create a PR shortly.