[Update] Remove mention of automated chunk adaptation in best practices

[mfreed]

Time intervals: The current release of TimescaleDB enables both the manual and automated 
adaption of its time intervals. With manually-set intervals, users should specify a
chunk_time_interval when creating their hypertable (the default value is 1 week).
The interval used for new chunks can be changed by calling set_chunk_time_interval().

Automated chunk adaptation has been deprecated for now, should be removed from docs

Location(s)
https://docs.timescale.com/latest/api#create_hypertable-best-practices