Configured GitHub to highlight HTML files as Django templates.

.gitattributes

@@ -5,3 +5,5 @@
 tests/staticfiles_tests/apps/test/static/test/*txt text eol=lf
 tests/staticfiles_tests/project/documents/test/*txt text eol=lf
 docs/releases/*.txt merge=union
+# Make GitHub syntax-highlight .html files as Django templates
+*.html linguist-language=django