Add fosstodon link to README.adoc #401

Job	Run time
build-and-verify (ubuntu-latest, 2.5, 8)	1m 13s
build-and-verify (ubuntu-latest, 2.5, 11)	1m 4s
build-and-verify (ubuntu-latest, 3.0, 8)	59s
build-and-verify (ubuntu-latest, 3.0, 11)	1m 0s
build-and-verify (ubuntu-latest, 3.0, 17)	1m 22s
build-and-verify (ubuntu-latest, 3.0, 21)	1m 31s
build-and-verify (ubuntu-latest, 4.0, 8)	1m 26s
build-and-verify (ubuntu-latest, 4.0, 11)	55s
build-and-verify (ubuntu-latest, 4.0, 17)	55s
build-and-verify (ubuntu-latest, 4.0, 21)	56s
build-and-verify (windows-latest, 2.5, 8)	3m 58s
build-and-verify (windows-latest, 3.0, 8)	2m 24s
build-and-verify (windows-latest, 4.0, 8)	2m 41s
build-and-verify (macos-latest, 2.5, 8)	1m 20s
build-and-verify (macos-latest, 3.0, 8)	1m 43s
build-and-verify (macos-latest, 4.0, 8)	3m 10s
release-spock (ubuntu-latest, 2.5, 8)	1m 31s
release-spock (ubuntu-latest, 3.0, 8)	1m 8s
release-spock (ubuntu-latest, 4.0, 8)	1m 31s
publish-release-docs (ubuntu-latest, 4.0, 21)	57s
	31m 44s

Provide feedback