Specify additional required information for build failures

.github/ISSUE_TEMPLATE.md

@@ -19,3 +19,8 @@ Make sure you have checked all steps below.
 - [ ] C Compiler information (e.g. gcc 7.3): 
 - [ ] Please attach the debug trace of the failing command as a gist:
   * Run `env PYENV_DEBUG=1 <faulty command> 2>&1 | tee trace.log` and attach `trace.log`. E.g. if you have a problem with installing Python, run `env PYENV_DEBUG=1 pyenv install -v <version> 2>&1 | tee trace.log` (note the `-v` option to `pyenv install`).
+- [ ] If you have a problem with installing Python, please also attach `config.log` from the build directory
+  * The build directory is reported after the "BUILD FAILED" message and is usually under `/tmp`.
+- [ ] If the build succeeds but the problem is still with the build process (e.g. the resulting Python is missing a feature), please attach
+  * the debug trace from reinstalling the faulty version with `env PYENV_DEBUG=1 pyenv install -f -k -v <version> 2>&1 | tee trace.log`
+  * `config.log` from the build directory. When using `pyenv install` with `-k` as per above, the build directory will be under `$PYENV_ROOT/sources`.