Add troubleshooting section to docs-build dev docs (backport #12804)

[mergify]

Summary

There are a couple of known failure modes for the documentation build that require additional setup. This documents these, to consolidate the knowledge.

Details and comments

See #12795 for an example.

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This is an automatic backport of pull request #12804 done by [Mergify](https://mergify.com).

[qiskit-bot]

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[coveralls]

Pull Request Test Coverage Report for Build 10060474682

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 19 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.02%) to 89.949%

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Files with Coverage Reduction	New Missed Lines	%
crates/qasm2/src/expr.rs	1	94.02%
crates/qasm2/src/lex.rs	6	92.88%
crates/qasm2/src/parse.rs	12	97.15%

Totals
Change from base Build 10040312664:	-0.02%
Covered Lines:	61851
Relevant Lines:	68762

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💛 - Coveralls