WIP: .NET Cheat Sheet spruce up

Update HTTP_Headers_Cheat_Sheet.md (#1167)

link fix (#1166)

Secure Cloud Architecture cheat sheet (#1152)

Replaced dead link in the Key Management Cheat Sheet (#1164)

Update Ruby_on_Rails_Cheat_Sheet.md (#1163)

Fix collapsible labels (#1162)

Minor modifications to Java cheatsheet (#1160)

Fix points which @szh raised in #1157 (#1161)

Add some pitfalls to the dotnet crypto code (#1159)

Initial start for prototype pollution prevention cheatsheet (#1157)

Creating dedicated Java Security Cheat Sheet (#1146)

Fix linting config (#1158)

Removed Encrypted CSRF Cookie (#1154)

Update markdown lint to allow collapsible sections (#1156)