Add .gitattributes to .gitignore

This allows individual contributors to add a .gitattributes for their needs, but opts for individualized .gitattributes per contributor.
Use case: One contributor is having an issue where, despite global git configuration, a lot of the line endings for files are getting converted to CRLF (Windows) rather than LF (Unix). The .gitattributes solution attempts to solve this, but since others aren't having this issue, it may be better to not bloat the repo by adding a file that it doesn't generally need.

.gitignore

@@ -16,6 +16,7 @@ semantic.cache/
 .vscode/*
 
 # - static
+.gitattributes
 .DS_Store
 
 # Specific files, patterns, and directories