[DOC beta] Fixes highlighting
[DOC beta] fixes for docs
[DOC beta] fixes formatting
Merge pull request #3984 from twokul/enumerable-fix

[DOC beta] Fixes highlighting
Merge pull request #3983 from twokul/mutable-array-fix

[DOC beta] fixes formatting
Merge pull request #3982 from twokul/mutable-array-fixes

[DOC beta] fixes for docs