Update command line options documentation to latest released version

Fix #3110: Add support for MCS 2.6.4 pinned region with array variable

* Added additional code to remove the conv instruction present in the initialization part of the pinned region.
* Extended the code responsible for removing the unpin stloc to correctly match the inverted condition found in MCS 2.6.4 compiled code.
* Enabled already present correctness test to run for MCS 2.6.4.

This is a more generalized version of the fix on PR #3110 proposed by @ElektroKill.

Fix #3108: illegal nested classes in enums throw off EnumValueDisplay…

…Mode handling.

Set version to 8.1.1

Fix #2891 Populate framework_dirs with the correct values depending o…

…n the current host runtime.

Set version for release

RC1 will be the next release

Merge pull request #2944 from cshung/public/support-composite-mode

Support disassembling ReadyToRun binaries compiled using composite mode

Merge pull request #2856 from ElektroKill/fix/pointer-post-increment

Improve support for post-increment/decrement on pointers

Fix #2751: Use correct icon for MemberSearchResult.

This has been broken since the ILSpyX refactoring.