chore(na): exclude URLs in link checker, fix 4.4.0 image, update graph

[mrjones-plip]

Description

In response to link checker report (see here and below):

Run chmod +x ./.github/scripts/*muffet*
http://localhost:1313/building/local-setup/
	403	https://scientyficworld.org/how-to-avoid-local-port-conflicts-in-docker/
http://localhost:1313/hosting/cht/kubernetes/gcp-multinode/
	502	https://www.geeksforgeeks.org/ulimit-soft-limits-and-hard-limits-in-linux/
http://localhost:1313/community/contributing/code/style-guide/
	403	http://news.ycombinator.com/item?id=1547647
http://localhost:1313/releases/4_4_0/
	404	http://localhost:1313/releases/images/4_4_0-8238.sync.improvements.png
Error: Process completed with exit code 1.

This PR:

• exclude URLs in link checker
• fix 4.4.0 image
• update graph title

License

The software is provided under AGPL-3.0. Contributions to this project are accepted under the same license.

[andrablaj]

☁️