Talk about input files coming from command line, the `read` command, and features provided by `RTLIL::Frontend` (making note that `read_slang` is a subclass but `ghdl` isn't).

Also dropping the `autosectionlabel_maxdepth = 1` so that I can actually use the auto section labels.
Adds warning on bash substitution on scripting intro page when talking about `yosys -p`.

Fix error on duplicated heading.
Drop `cmd_ref`_ link (everything already uses :doc:`cmd_ref`).

Add a note on fuzzers, with a polite suggestion that if you're fuzzing you should put in the work of identifying the underlying issue so that you (and we) are confident you're not raising multiple issues for the same bug.

Was previously in yosys_internals which is more developer focused, rather than user focused.

Also some other tidy up and clarifications.

What do I do with the minimized design and (the first half of) Minimizing scripts

More info for creating GitHub issues and the different sections.
Discuss additional details that can be included as comments on the issue.  Also mention Gists for large files (preferable to downloading a .txt).
Add a warning about external plugins/tools.
Also add a note to `load_design.rst` about `Frontend`s and `-f` command line option.

I just missed that it only gets included in the makefile if `DISABLE_SPAWN` is set, because I was looking for the C define `YOSYS_DISABLE_SPAWN`.

part 2: electric boogaloo

Move `yosys -h bugpoint` failure into a code-block to break up text.  Same for the `exec -expect-return` example.
TODOs on #5068 being merged.

Move the "creating an issue" section from bugpoint.rst to "reporting bugs" in `contributing.rst`.
Fix link to `CONTRIBUTING.md`.
Update `CONTRIBUTING.md` to refer to the bugpoint guide instead of the stack overflow guide.

Minimizing scripts (and more generally identifying root cause) isn't necessary for regular bug reports.  Rather, it can be useful for developers working on *fixing* bugs, and also for fuzzers to avoid spam.
Minor adjustments to `bugpoint.rst`.
Add note to `advanced_bugpoint.rst` about primitives when minimizing scripts.

Update text to assume bugpoint PR changes.

Also fix missing double backtick.