Update PULL_REQUEST_TEMPLATE.md

Updated the template sample to align with the advised character limit of "80".  Sample had indicated a different value and now aligns with the advice outlined: "...under 80 characters, sentence..."

.github/PULL_REQUEST_TEMPLATE.md

@@ -12,7 +12,7 @@ To ensure your PR is dealt with swiftly please check the following:
   Keep the short description under 80 characters and use [sentence case](https://en.wikipedia.org/wiki/Letter_case#Sentence_case)
   for it, even if the project's webpage or readme uses another capitalisation.
   `Demo` links should only be used for interactive demos, i.e. not video demonstrations.
-  ``- [Name](http://homepage/) - Short description, under 250 characters, sentence case. ([Demo](http://url.to/demo), [Source Code](http://url.of/source/code), [Clients](https://url.to/list/of/related/clients-or-apps)) `License` `Language` ``
+  ``- [Name](http://homepage/) - Short description, under 80 characters, sentence case. ([Demo](http://url.to/demo), [Source Code](http://url.of/source/code), [Clients](https://url.to/list/of/related/clients-or-apps)) `License` `Language` ``
 - [ ] Additions are inserted preserving alphabetical order.
 - [ ] Additions are not already listed at [awesome-selfhosted](https://awesome-selfhosted.net)
 - [ ] The `Language` tag is the main **server-side** requirement for the software. Don't include frameworks or specific dialects.