.gitignore: add public/.well-known directory (#1335)

RFC 5785 defines /.well-known/ as the prefix for "well-known locations"
in URIs. This prefix is used for example by Certbot/Let's Encrypt to
request SSL certificates. PartDB doesn't need to care about this
directory, but also should not see its existence as the git tree being
"dirty".

Author: klausman

.gitignore

@@ -25,6 +25,10 @@
 uploads/*
 !uploads/.keep
 
+# Some people use Certbot or similar tools to make SSL certificates.
+# Also see https://www.rfc-editor.org/rfc/rfc5785
+public/.well-known/
+
 # Do not keep cache files
 .php_cs.cache
 .phpcs-cache
@@ -50,4 +54,4 @@ phpstan.neon
 ###< phpstan/phpstan ###
 
 .claude/
-CLAUDE.md
+CLAUDE.md