pull_request_template.md: restore indentation

This partially reverts commit 3754680 ("docs: remove indents on
top-level lists and tables", 2023-02-01) from PR #5674.

Commands used to undo the changes:

    $ f=.github/pull_request_template.md; \
      git show 3754680~1:"$f" >"$f"

I had assumed that a blank line after a list item would end the list
(and so I was confused by the amount of indentation used), but that is
apparently not the case.  See the file rendered before/after the
commit[1] [2].

Relates to #2784.

Reported by @rusty-snake[3].

[1] https://github.com/netblue30/firejail/blob/f5d8d8cc7af8f8816c47623515babcefceb7e22f/.github/pull_request_template.md
[2] https://github.com/netblue30/firejail/blob/37546800876d977d77cc86d9b307f8cfa714c1dd/.github/pull_request_template.md
[3] #5674 (comment)

.github/pull_request_template.md

@@ -1,17 +1,17 @@
 If your PR isn't about profiles or you have no idea how to do one of these, skip the following and go ahead with this PR.
 
 If you submit a PR for new profiles or changing profiles, please do the following:
-- The ordering of options follow the rules described in [/usr/share/doc/firejail/profile.template](https://github.com/netblue30/firejail/blob/master/etc/templates/profile.template).
-> Hint: The profile-template is very new. If you install firejail with your package manager, it may be missing. In order to follow the latest rules, it is recommended to use the template from the repository.
-- Order the arguments of options alphabetically. You can easily do this with [sort.py](https://github.com/netblue30/firejail/tree/master/contrib/sort.py).
-The path to it depends on your distro:
+ - The ordering of options follow the rules described in [/usr/share/doc/firejail/profile.template](https://github.com/netblue30/firejail/blob/master/etc/templates/profile.template).
+   > Hint: The profile-template is very new. If you install firejail with your package manager, it may be missing. In order to follow the latest rules, it is recommended to use the template from the repository.
+ - Order the arguments of options alphabetically. You can easily do this with [sort.py](https://github.com/netblue30/firejail/tree/master/contrib/sort.py).
+ The path to it depends on your distro:
 
-| Distro | Path |
-| ------ | ---- |
-| Arch/Fedora | `/usr/lib64/firejail/sort.py` |
-| Debian/Ubuntu/Mint | `/usr/lib/x86_64-linux-gnu/firejail/sort.py` |
-| local git clone | `contrib/sort.py` |
+   | Distro | Path |
+   | ------ | ---- |
+   | Arch/Fedora | `/usr/lib64/firejail/sort.py` |
+   | Debian/Ubuntu/Mint | `/usr/lib/x86_64-linux-gnu/firejail/sort.py` |
+   | local git clone | `contrib/sort.py` |
 
-Note also that the sort.py script exists only since firejail `0.9.61`.
+   Note also that the sort.py script exists only since firejail `0.9.61`.
 
 See also [CONTRIBUTING.md](/CONTRIBUTING.md).