Add a pre-commit hook configuration to check YAML and whitespace.

These are minor, but avoids those coming up during reviews at all.

.pre-commit-config.yaml

@@ -11,3 +11,9 @@ repos:
     rev: latest
     hooks:
     - id: reuse
+-   repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v2.3.0
+    hooks:
+    -   id: check-yaml
+    -   id: end-of-file-fixer
+    -   id: trailing-whitespace

CODE_OF_CONDUCT.md

@@ -49,7 +49,7 @@ Examples of unacceptable behavior by participants include:
 
 The goal of the standards and moderation guidelines outlined here is to build
 and maintain a respectful community. We ask that you don’t just aim to be
-"technically unimpeachable", but rather try to be your best self. 
+"technically unimpeachable", but rather try to be your best self.
 
 We value many things beyond technical expertise, including collaboration and
 supporting others within our community. Providing a positive experience for
@@ -80,9 +80,9 @@ You may report in the following ways:
 In any situation, you may send an email to <[email protected]>.
 
 On the Adafruit Discord, you may send an open message from any channel
-to all Community Moderators by tagging @community moderators. You may 
-also send an open message from any channel, or a direct message to 
-@kattni#1507, @tannewt#4653, @Dan Halbert#1614, @cater#2442, 
+to all Community Moderators by tagging @community moderators. You may
+also send an open message from any channel, or a direct message to
+@kattni#1507, @tannewt#4653, @Dan Halbert#1614, @cater#2442,
 @sommersoft#0222, @Mr. Certainly#0472 or @Andon#8175.
 
 Email and direct message reports will be kept confidential.