Add documentation for `firstkey`, `lastkey` and `keystep` parameters of `RedisModule_CreateCommand` (#8883)
Add documentation for `firstkey`, `lastkey` and `keystep` parameters of `RedisModule_CreateCommand` (#8883)

These parameters of RedisModule_CreateCommand were previously
undocumented but they are needed for ACL to check permission on keys and
by Redis Cluster to figure our how to route the command.

Co-authored-by: Eduardo Felipe Castegnaro <0467e1e56fdd5d1e04d90b7eacd241d17bcdc004@onsign.tv>
Co-authored-by: Oran Agra <4bc4982385244a2789f53ac695e2aa0ced00df6d@redislabs.com>
yossigo/redis,ofirluzon/redis,neomantra/redis,charsyam/redis,antirez/redis,yossigo/redis,PKRoma/redis,neomantra/redis,soloestoy/redis,charsyam/redis,oranagra/redis,soloestoy/redis,ofirluzon/redis,charsyam/redis,soloestoy/redis,oranagra/redis,antirez/redis,neomantra/redis,PKRoma/redis,ofirluzon/redis,charsyam/redis,yossigo/redis,antirez/redis,ofirluzon/redis,neomantra/redis,PKRoma/redis,soloestoy/redis,yossigo/redis,neomantra/redis,oranagra/redis,oranagra/redis,soloestoy/redis,charsyam/redis,PKRoma/redis,oranagra/redis,ofirluzon/redis,antirez/redis,PKRoma/redis,yossigo/redis