Add RPCs added in 0.21

Author: cornelius

helpers/rpc/annotations-bitcoin-0.21.json

@@ -362,6 +362,9 @@
       ]
     }
   },
+  "getindexinfo": {
+    "added": "0.20"
+  },
   "getinfo": {
     "removed": "0.16.0",
     "see_also": {
@@ -857,6 +860,9 @@
   "submitheader": {
     "added": "0.18.0"
   },
+  "upgradewallet": {
+    "added": "0.21"
+  },
   "utxoupdatepsbt": {
     "added": "0.18.0"
   },