issue template: Update bug report template to include useful info

Our current bug template is almost the same as our feature request template. This leads to users not always providing the information we need to act on a bug.

This commit updates the template so that users will
be able to provide more detailed bug reports without blank
or placeholder lines.

.gitlab/issue_templates/Bug.md

@@ -6,14 +6,19 @@ Steps to reproduce:
 2. Enter a room
 3. ...
 
-## Design Tasks
+* [ ] This bug is reproducible from the latest nightly build <!-- Check this box if the bug happens on Fractal's development version -->
 
-* [ ]  design tasks
+**Fractal Version**: <!-- The version of Fractal you were using when the bug occurred. Check the "About Fractal" dialog for this information -->
 
-## Development Tasks
+**OS Version**: <!-- Operating system version, e.g. Fedora 31 -->
 
-* [ ]  development tasks
+**Installation Source**: <!-- Where you installed Fractal from, e.g. Flathub, AUR, or distro repositories -->
 
-## QA Tasks
+<!-- If you have a crash report, use the "Attach A File" button in the issue editor to attach it, or paste it in a code block below. -->
+<!-- To create a code block, you surround the code with two lines with three "`" characters like so:
 
-* [ ]  quality assurance tasks
+```
+code goes here
+```
+
+-->