Is your feature request related to a problem? Please describe.
Projects that maintaining multiple major / minor versions at the same time end up with semantic unordered changelogs with not working diffs likev4.0.0 tov3.5.10 becausev3.5.10 has been released afterv4.0.0.

Describe the solution you'd like
Flag to switch to a semantic version ordering.

Current ordering based on tag date:v3.5.9, v4.0.0, v3.5.10, v4.1.0
Wanted ordering based on semantic Versioning:v3.5.9, v3.5.10, v4.0.0, v4.1.0

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
https://github.com/github-changelog-generator/github-changelog-generator/blob/master/lib/github_changelog_generator/generator/generator_tags.rb#L12