Update docs links for new URL structure (backport #12896)

[mergify]

Part of Qiskit/documentation#1461. Even though these pages have redirects, it's better to go straight to the page we want.

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This is an automatic backport of pull request #12896 done by Mergify.

[qiskit-bot]

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[coveralls]

Pull Request Test Coverage Report for Build 10222301894

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 6 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.02%) to 89.964%

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Files with Coverage Reduction	New Missed Lines	%
crates/qasm2/src/expr.rs	1	94.02%
crates/qasm2/src/lex.rs	5	92.48%

Totals
Change from base Build 10221777333:	0.02%
Covered Lines:	66745
Relevant Lines:	74191

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💛 - Coveralls