[Docs RFC] Unite some get started pages into one

[billy-the-fish]

Unite the following into one page:
https://docs.timescale.com/getting-started/latest/tables-hypertables/
https://docs.timescale.com/getting-started/latest/time-series-data/
https://docs.timescale.com/getting-started/latest/queries/
https://docs.timescale.com/getting-started/latest/aggregation/

Suggest / Console data import / livesync / data generation for tests.