Update installation template

Taking a few pages from bat's book.

Author: victor-gp

.github/ISSUE_TEMPLATE/installation.md

@@ -1,108 +1,33 @@
 ---
 name: Installation Issue
 about: The syntax doesn't work after you tried the installation steps.
-title: 'Installation: [TITLE]'
+title: ''
 labels: installation
 assignees: ''
----
-
-### environment:
-
-Output of `$ bat --diagnostic`:
-
-<!--
-Example:
-
-#### Software version
-
-bat 0.22.1
-
-#### Operating system
-
-Linux 5.15.0-76-generic
 
-#### Command-line
-
-```bash
-bat --diagnostic
-```
-
-#### Environment variables
-
-```bash
-SHELL=/usr/bin/zsh
-PAGER=less
-LESS=<not set>
-LANG=en_US.UTF-8
-LC_ALL=<not set>
-BAT_PAGER='less -R'
-BAT_CACHE_PATH=<not set>
-BAT_CONFIG_PATH=<not set>
-BAT_OPTS=<not set>
-BAT_STYLE=<not set>
-BAT_TABS=<not set>
-BAT_THEME=<not set>
-XDG_CONFIG_HOME=<not set>
-XDG_CACHE_HOME=<not set>
-COLORTERM=truecolor
-NO_COLOR=<not set>
-MANPAGER='sh -c '\''col -bx | bat -p --language=man --theme=custom16'\'''
-```
-
-#### System Config file
-
-Could not read contents of '/etc/bat/config': No such file or directory (os error 2).
+---
 
-#### Config file
+**What happens?**
 
-```
-# This is `bat`s configuration file. Each line either contains a comment or
-# a command-line option that you want to pass to `bat` by default. You can
-# run `bat --help` to get a list of all possible configuration options.
+...
 
---theme="Dracula"
---italic-text=always
---color=always
-```
+**What did you expect to happen instead?**
 
-#### Custom assets metadata
+...
 
-```
 ---
-bat_version: 0.22.1
-creation_time:
-  secs_since_epoch: 1675707991
-  nanos_since_epoch: 145212003
-```
-
-#### Custom assets
 
-- metadata.yaml, 101 bytes
-- syntaxes.bin, 907088 bytes
-- themes.bin, 41171 bytes
+**bat version and environment**
 
-#### Compile time information
-
-- Profile: release
-- Target triple: x86_64-unknown-linux-gnu
-- Family: unix
-- OS: linux
-- Architecture: x86_64
-- Pointer width: 64
-- Endian: little
-- CPU features: fxsr,sse,sse2
-- Host: x86_64-unknown-linux-gnu
+<!--
+In order to reproduce your issue, please add some information about the environment
+in which you're running bat. To do this, run the full `bat` command that demonstrates
+the bug, and attach the `--diagnostic` option:
 
-#### Less version
+    bat [other options and arguments…] --diagnostic
 
-```
-> less --version
-less 551 (GNU regular expressions)
-Copyright (C) 1984-2019  Mark Nudelman
+Finally, paste the Markdown output here. Please make sure that it does not reveal any
+personal information.
 
-less comes with NO WARRANTY, to the extent permitted by law.
-For information about the terms of redistribution,
-see the file named README in the less distribution.
-Home page: http://www.greenwoodsoftware.com/less
-```
+If you are on Windows, please let us know your bat version and your Windows version.
 -->