Make bug report template easier to fill (#4076)

* Make bug report template easier to fill

This is an attempt to make it easier for users to fill out the bug
report template by requiring less edits to copy-paste the relevant
information.

Hopefully, this translates into better reports that deviate less from
the template and less friction for maintainers to triage issues.

* Drop node_modules questions from bug report template

Based on feedback from Steffen.

Probably the info is not very relevant in most cases.

Author: rhcarvalho

.github/ISSUE_TEMPLATE/bug_report.md

@@ -9,12 +9,23 @@ assignees: ''
 
 ### Environment
 
-* Elixir version (elixir -v):
-* Phoenix version (mix deps):
-* Phoenix LiveView version (mix deps):
+* Elixir version (please paste the output of `elixir -v`):
+```
+
+```
+* Phoenix and LiveView versions (`mix deps | grep -w 'phoenix\|phoenix_live_view'`):
+```
+
+```
 * Operating system:
-* Browsers you attempted to reproduce this bug on (the more the merrier): 
-* Does the problem persist after removing "assets/node_modules" and trying again? Yes/no:
+- [ ] Windows
+- [ ] MacOS
+- [ ] Linux
+- [ ] Other (please specify): 
+* Browsers (including version) you attempted to reproduce this bug on (the more the merrier):
+```
+
+```
 
 ### Actual behavior