Commits current write transaction
If not used, write transaction, once finished, will be discarded. Only valid within WRITE's scope.
PumpkinDB> ["hi" "there" ASSOC] WRITE ["hi" "there" ASSOC COMMIT] WRITE
In this example, the second transaction did not fail with a duplicate key error because the first one never committed the change.
NoTransaction error if there's no current write transaction
change : "hi" DUP "there" [ASSOC COMMIT] WRITE [ASSOC?] READ. otherwise_no_change : "hi" DUP "there" [ASSOC] WRITE [ASSOC?] READ NOT. commit_requires_txn : [COMMIT] TRY UNWRAP 0x08 EQUAL?. commit_requires_write_txn : [[COMMIT] READ] TRY UNWRAP 0x08 EQUAL?.