Correct max-age value for HSTS header

Summary

At some point recently, the default value for the Strict-Transport-Security (aka HSTS) header was changed from 63072000 (730 days) to 31536000 (365 days). This release fixes that oversight.

What's Changed

• Added .github dir to ignore for action by @GaProgMan in #101
• scorecard.yml updated to latest best-practise by @GaProgMan in #102
• Added warnings as errors to csproj files by @jamie-taylor-rjj in #104
• Initial commit of the Just-The-Docs template files by @GaProgMan in #106
• Fixed URL in config for docs directory by @GaProgMan in #110
• Initial Customisation of docs theme by @GaProgMan in #111
• Fixed location of logo in docs config by @GaProgMan in #112
• Bugfix/docs logo location by @GaProgMan in #113
• Feature/basic docs by @GaProgMan in #114
• Feature/basic docs by @GaProgMan in #115
• Feature/basic docs by @GaProgMan in #116
• Feature/basic docs by @GaProgMan in #117
• Fixed gemfile.lock by @jamie-taylor-rjj in #118
• Very basic documentation files by @GaProgMan in #119
• Feature/docs basic entries by @GaProgMan in #120
• The max-age value used by the default HSTS header is no longer correct by @jamie-taylor-rjj in #121

Full Changelog: v9.0.0...v9.1.0