Update bug_report.md (#4860)

Some issues lately have been shockingly devoid of useful information...
- Reintroduce environment questions inspired by standard template, albeit simpler
- That details trick to make large saved games manageable is already used by some, it *could* work in the hands of the masses - or too dangerous?

.github/ISSUE_TEMPLATE/bug_report.md

@@ -7,6 +7,12 @@ assignees: ''
 
 ---
 
+**Platform**
+Operating system type, major version, architecture (64/32 bit).
+
+**Version**
+Where you got the game and the exact version number.
+
 **Describe the bug**
 A clear and concise description of what the bug is.
 
@@ -17,7 +23,13 @@ Steps to reproduce the behavior:
 3. Scroll down to '....'
 4. See error
 
-If game data is required, please add from menu, save game, copy to clipboard, paste here
+If game data is required, please add it here. From the menu, choose save game (or map), copy to clipboard, and paste here between the backtick blocks (or, if no such save is required, you may delete this):
+<details><summary>Saved game</summary>
+
+```
+
+```
+</details>
 
 **Expected behavior**
 A clear and concise description of what you expected to happen.