message: Update readme supported frames. Add Register and Event
diff: @@ -32,7 +32,7 @@ into Rust structures It supports 4-th version of [Cassandra protocol](https://gi
  - [x] PREPARE
  - [x] EXECUTE
  - [ ] BATCH
  -- [ ] REGISTER
  +- [x] REGISTER
  #### Response
  @@ -55,7 +55,7 @@ into Rust structures It supports 4-th version of [Cassandra protocol](https://gi
  * - [x] Target FUNCTION
  * - [x] Target AGGREGATE
  -- [ ] EVENT
  +- [x] EVENT
  - [x] AUTH_CHALLENGE
  - [x] AUTH_SUCCESS
  