Update Sphinx

- Bump versions in requirements.txt

Remove sphinx docs which were duplicated everywhere, refer to ONF main
docs site which is more complete.

Replace logo with SVG version
- Was a WebP saved as .png which broke in some browsers.
- Shift logo to sidebar, as in all other docs sites.

Cleanup Makefile

Change how the dict.txt sorter works
- Only check the dict.txt for changes
- Give human-intelligible results

Add correct licensing info for fonts

Add code of conduct and link

Change-Id: Ie4334cfea826e348eca4c93ed62a3633b33ad87c
diff --git a/requirements.txt b/requirements.txt
index ab1a4f4..00bce7f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,11 +1,10 @@
 # SPDX-FileCopyrightText: 2021 Open Networking Foundation <info@opennetworking.org>
 # SPDX-License-Identifier: Apache-2.0
 
-Sphinx~=4.1.2
-doc8~=0.9.0
-reuse~=0.13.0
-docutils==0.16
-sphinx-rtd-theme~=0.5.2
-sphinxcontrib-spelling~=7.2.1
+Sphinx~=4.4.0
+doc8~=0.10.1
+docutils~=0.17.1
+reuse~=0.14.0
+sphinx-rtd-theme~=1.0.0
+sphinxcontrib-spelling~=7.3.2
 sphinx-multiversion~=0.2.4
-sphinx-reload~=0.2.0