Add info about upgrades to GitHub issue template.

Thanks to xet7 !

.github/ISSUE_TEMPLATE.md

@@ -1,12 +1,14 @@
 ## Issue
 
-Note: With Docker, please don't use latest tag. Only use release tags.
-See https://github.com/wekan/wekan/issues/3874
+**[PLEASE UPGRADE](https://github.com/wekan/wekan/wiki/Backup)** to newest WeKan before adding new issue:
+- Usually bugs are already fixed, we get too many duplicate reports.
+- Please search existing Open and Closed issues, most questions have
+  already been answered many times.
 
 If you can not login for any reason:
 - https://github.com/wekan/wekan/wiki/Forgot-Password
 
-Email settings:
+Email settings, only SMTP MAIL_URL and MAIL_FROM are in use:
 - https://github.com/wekan/wekan/wiki/Troubleshooting-Mail
 
 Add these issues to elsewhere:
@@ -20,14 +22,12 @@ Other Wekan issues can be added here.
 * Note: Please anonymize info, and do not add to this public issue any of your Wekan board URLs, passwords, API tokens etc, do you understand?:
 * Did you test in newest Wekan?:
 * For new Wekan install, did you configure root-url correctly so Wekan cards open correctly https://github.com/wekan/wekan/wiki/Settings ?
-* Wekan version:
-* If this is about old version of Wekan, what upgrade problem you have?:
 * Operating System:
-* Deployment Method(snap/docker/sandstorm/mongodb bundle/source):
+* Deployment Method(Snap/Docker/Sandstorm/bundle/source):
 * Http frontend if any (Caddy, Nginx, Apache, see config examples from Wekan GitHub wiki first):
-* Node Version:
+* Node.js Version:
 * MongoDB Version:
-* Wekan only works on newest desktop Firefox/Chromium/Chrome/Edge/Chromium Edge and mobile Chrome. What webbrowser version are you using?
+* Wekan works on newest desktop and mobile webbrowsers that support Javascript. What webbrowser version are you using?
 
 **Problem description**:
 - *REQUIRED: Add recorded animated gif about how it works currently, and screenshot mockups how it should work. Use peek to record animgif in Linux https://github.com/phw/peek*