[quant][docs] Fix formatting for quantization.rst (#76223)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/76223
Small formatting fixes that was missed because I didn't check the generated doc last time
Test Plan:
visual inspection of the generated docs for this PR
Imported from OSS
Reviewed By: HDCharles
Differential Revision: D35853174
fbshipit-source-id: 4454a4bf5d0c998d866bbae1d6b5286827082033
(cherry picked from commit 125f60356ccc9cd6888c515889bd27ff9860ec74)
