docs: db type mappings #2043

Job	Run time
Build `sea-query-binder` (async-std, rustls)	1m 57s
Build `sea-query-postgres`	48s
Clippy	1m 8s
Build `sea-query`	45s
Build `sea-query-rusqlite`	48s
Rustfmt	15s
Unit Test	1m 45s
Derive Tests	41s
MariaDB (10.6, sqlx_mysql)	1m 10s
Any	1m 3s
MySQL (8, sqlx_mysql)	1m 23s
SQLite (rusqlite)	19s
MySQL (5.7, sqlx_mysql)	1m 17s
PostgreSQL (14.4, postgres)	47s
SQLite (sqlx_sqlite)	1m 1s
PostgreSQL (14.4, sqlx_postgres)	1m 10s
PostgreSQL (13.7, postgres)	44s
PostgreSQL (13.7, sqlx_postgres)	1m 17s
PostgreSQL (12.11, postgres)	48s
PostgreSQL (12.11, sqlx_postgres)	1m 11s
	20m 17s

Provide feedback