Rewrite contributing guide and add two troubleshooting soulutions

[CorvidCanine]

Moved bug reporting guidelines to its own page, updated the code contribution guide to include the many notes at the end as actual steps. Adding tests and documentation probably shouldn't be in a note at the end.

This could have been in its own PR but I'm including it here; Added two a solutions to issues that may arise when installing that I came across when trying to get manim to run in Raspbian.

Changes

• Move bug reporting guidelines from contributing.md to reporting_bugs.rst
• Add reporting_bugs.rst to the index toxtree
• Add links to the repo issue page and discord server in reporting_bugs.rst
• Rewrite of the guide in contributing.md
• Add direction of developers from installation.rst to contributing.md.
• Add potential solution to missing letter from TexMobjects due to unbuilt TeX fonts in troubleshooting.rst
• Add potential solution to "LaTeX' in the OpeningManimExample displaying incorrectly due to missing python to cairo binds.

Motivation

The code contributing guidelines were unclear and did not include important steps as actual steps.
Finding the guide to report bugs should be very easy to access.

Testing Status

make doctest only reports errors for python objects not included in the toctree, which I'm not going to add in this PR.

Acknowledgement

• I have read the Contributing Guidelines
• And I just rewrote them... so yes to both versions :)?

[naveen521kk]

Some comments,

[huguesdevimeux]

Converting this to draft

[leotrs]

BTW, the contributing guidelines have moved to docs/source/contributing.md. Please merge from master and update this PR :)

[CorvidCanine]

Thank you for looking through everything @naveen521kk. I've made the changes you suggested, except for the installation link from contributing.md. I'm not sure what's wrong with it?
The python-cario bindings fixed the issue for me on Raspbian, but I've removed it until I/someone can do more research into this.
@leotrs Thank's for pointing out the file move.

[leotrs]

Hmm for some reason your PR is now listing 302 files changed 😅 It might be easier to branch again from a fresh master and rebase your commits, if that's at all possible on your end :)

[CorvidCanine]

After a not-so-elegant attempt at a rebase, github should now be showing 5 file changes by 1 new commit.

[leotrs]

LGTM! Please fix @naveen521kk 's suggestion.

@naveen521kk, if you think this is ready, let me know and I'll merge!

[naveen521kk]

Some small suggestion

[naveen521kk]

Looks good for me. Just a reminder to myself that I need to edit these in #165

[leotrs]

Thank you @CorvidCanine ! We look forward to your future contributions :)