docs: add naming rules for databases, namespaces, tables and views

One page states the characters and lengths each kind of name can have,
following the rules lancedb #4490 centralizes, with examples. It says
what enforces them today: the embedded library checks table characters
but not length, a directory namespace accepts more, the SDKs check
db:// names only from the first release that includes #4490 (none yet),
and a deployment can accept a longer name at creation and fail on it
later. Readers are told to keep to the rules regardless. Limits, table
creation and namespaces link to it.

docs/web/docs.json

@@ -272,7 +272,8 @@
               "basics/jobs",
               "tables/consistency",
               "basics/guarantees",
-              "basics/limits"
+              "basics/limits",
+              "basics/naming"
             ]
           },
           {