Move pull request template to github directory (#991)

This file is part of the github workflow and not the documentation
so for consistency reason be moved to `.github` to be accompanied
with the issue template.

Author: sliverc

docs/pull_request_template.md renamed to .github/pull_request_template.md

@@ -88,7 +88,7 @@
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
-exclude_patterns = ["_build", "pull_request_template.md"]
+exclude_patterns = ["_build"]
 
 # The reST default role (used for this markup: `text`) to use for all
 # documents.