typo fixes found by @niftynei

Also, put the "added" lines in the request schemas for new commands:
this doesn't do anything (yet?) but it keeps `make schema-added-check` happy.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

doc/schemas/sql.request.json

@@ -4,6 +4,7 @@
   "required": [
     "query"
   ],
+  "added": "v23.02",
   "properties": {
     "query": {
       "type": "string"