[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.