UX: add link to robots.txt editor in site setting description

UX: add link to robots.txt editor in site setting description

This surfaces our robots.txt editor and provides enough warning to scare people from actually changing it.

diff --git a/config/locales/server.en.yml b/config/locales/server.en.yml
index 6aa5601..af22aa6 100644
--- a/config/locales/server.en.yml
+++ b/config/locales/server.en.yml
@@ -1478,7 +1478,7 @@ en:
     enable_badges: "Enable the badge system"
     enable_whispers: "Allow staff private communication within topics."
 
-    allow_index_in_robots_txt: "Specify in robots.txt that this site is allowed to be indexed by web search engines."
+    allow_index_in_robots_txt: "Specify in robots.txt that this site is allowed to be indexed by web search engines. In exceptional cases you can permanently <a href='%{base_path}/admin/customize/robots'>override robots.txt</a>."
     email_domains_blacklist: "A pipe-delimited list of email domains that users are not allowed to register accounts with. Example: mailinator.com|trashmail.net"
     email_domains_whitelist: "A pipe-delimited list of email domains that users MUST register accounts with. WARNING: Users with email domains other than those listed will not be allowed!"
     hide_email_address_taken: "Don't inform users that an account exists with a given email address during signup and from the forgot password form."

GitHub sha: 6374dc7d