docs: flesh out the catalog Extending the model section (#3352)

.github/styles/vocab.txt

@@ -1,9 +1,9 @@
 abc
+andrewthauer
 Apdex
 api
 Api
 apis
-andrewthauer
 args
 asciidoc
 async
@@ -12,20 +12,22 @@ backrub
 Balachandran
 benjdlambert
 Bigtable
+Billett
 Blackbox
 bool
 boolean
+builtins
 Chai
 changeset
 changesets
 Changesets
-changset
 chanwit
 Chanwit
 cisphobia
 cissexist
 classname
 cli
+cloudbuild
 cncf
 codeblocks
 Codecov
@@ -68,6 +70,7 @@ github
 Github
 gitlab
 Gitlab
+Grafana
 graphql
 graphviz
 Gustavsson
@@ -79,6 +82,7 @@ horizontalpodautoscalers
 Hostname
 http
 https
+Iain
 img
 incentivised
 inlined
@@ -98,8 +102,8 @@ learnings
 lerna
 Lerna
 magiclink
-Maintainership
 mailto
+maintainership
 Malus
 md
 microsite
@@ -116,6 +120,7 @@ msw
 namespace
 namespaces
 Namespaces
+namespacing
 neuro
 newrelic
 nginx
@@ -175,6 +180,7 @@ semver
 Serverless
 Sinon
 smartsymobls
+Snyk
 sparklines
 Spotifiers
 spotify
@@ -215,15 +221,10 @@ Voi
 Wealthsimple
 Weaveworks
 Webpack
+www
+WWW
 xyz
 yaml
 Zalando
 Zhou
 Zolotusky
-Billett
-cloudbuild
-Grafana
-Iain
-Snyk
-www
-WWW