[x265] Issue #521: analysis-reuse-mode not documented (multicoreware/x265)

[Lastique]

New issue 521: analysis-reuse-mode not documented
https://bitbucket.org/multicoreware/x265/issues/521/analysis-reuse-mode-not-documented

Andrey Semashev:

In a few places of command line options documentation \(https://x265.readthedocs.io/en/default/cli.html\) the \`--analysis-reuse-mode\` option is mentioned, but it is not documented. If that option doesn’t exist, its references should be removed, otherwise it should be documented.