.gitattributes: explicitly denote specific file extensions as 'text'

Configure auto-clrf for all text files. This should make it simpler to
develop Flamenco on Windows, as it makes Git depend less on its global
settings.

.gitattributes

@@ -3,3 +3,32 @@
 /addon/flamenco/manager_README.md linguist-generated=true
 /web/app/src/manager-api/** linguist-generated=true
 **/*.gen.go linguist-generated=true
+
+# Set the default newline behavior, in case people don't have core.autocrlf set.
+* text=auto
+
+*.cjs text
+*.css text
+*.csv text
+*.go text
+*.html text
+*.ini text
+*.js text
+*.json text
+*.map text
+*.md text
+*.py text
+*.sh text
+*.svg text
+*.toml text
+*.txt text
+*.vue text
+*.webapp text
+*.webmanifest text
+*.xml text
+*.yaml text
+/go.mod text
+/go.sum text
+/LICENSE text
+/Makefile text
+/VERSION text