docs: uppdated getting started with images and text, added info on query inspector to version45 and trouble shooting (#9193)

add new dashboard shortcut

added CloudWatch data source API documentation

Optimize some wrong usage and spelling

Signed-off-by: wgliang <liangcszzu@163.com>

* (prometheus) cache metric suggest query result

* add test

* Prometheus: Fix actual step computation logic when a min_step is specified and the range is longer than min_step * 11000.

* Have the 'Hide series with only zeros' option also apply to series with some null values.

Fixing type of parameters from "select" to "boolean" for working with carbonapi (like it was done in summarize function) + some commas prettify.

Make it clearer that it only works with basic auth

Add the missing step of "grunt build" to the README.md

- use charset would issue additional 'SET NAMES <VALUE>' queries, set
collation would be better. see: https://github.com/go-sql-driver/mysql#charset