Serve docs at lokf.nolan-nichols.com

The apex/www domain (www.nolan-nichols.com) is served by the personal-site
repo (nicholsn.github.io); a second repo can't share that custom domain, so
point the docs at their own subdomain instead of the /lokf/ subpath.

- mkdocs site_url -> https://lokf.nolan-nichols.com/
- docs/CNAME so `mkdocs build` emits CNAME for the Pages custom domain
- README documentation link updated

Manual follow-up: add a DNS CNAME record lokf.nolan-nichols.com ->
nicholsn.github.io, and set this repo's Pages custom domain to
lokf.nolan-nichols.com.

Author: nicholsn

README.md

@@ -9,7 +9,7 @@ ontology are all generated from that single source.
 
 > One sentence: *write OKF markdown, get a queryable knowledge graph for free.*
 
-**Documentation:** <https://www.nolan-nichols.com/lokf/>
+**Documentation:** <https://lokf.nolan-nichols.com/>
 
 ## Why
 

docs/CNAME

@@ -0,0 +1 @@
+lokf.nolan-nichols.com

mkdocs.yml

@@ -2,7 +2,7 @@ site_name: LOKF — Linked Open Knowledge Format
 site_description: >-
   A semantic profile of Google's Open Knowledge Format: write OKF markdown,
   get a queryable knowledge graph for free.
-site_url: https://www.nolan-nichols.com/lokf/
+site_url: https://lokf.nolan-nichols.com/
 repo_url: https://github.com/nicholsn/lokf
 repo_name: nicholsn/lokf
 edit_uri: edit/main/docs/