You need to set the following in your homeserver.yaml
:
serve_server_wellknown: true
read more here: https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html#serve_server_wellknown
Also remember to restart your container.
I had you till you got to running your blog on google sites. Like not even blogger, but straight up google sites. As someone who tried using google sites for this purpose, I wrote one post and I was like, not doing it, it is too much.