add more detail to the environment-variable docs

[oregonpillow]

I think the environment-variables could be improved in both format and content.

At a minimum i feel that each variable in the table should additionally have a type specified (bool, string, int) and at least 1 valid example. This is especially true for the datetime formatting.

For example:

• what format do i use to specify APP_TIMEZONE ? Docs say nothing about this.
• CHART_DATETIME_FORMAT , DATETIME_FORMAT : a couple of common examples would probably satisfy 99% of use cases and save users from wading through PHP docs
• DISPLAY_TIMEZONE: I'm assuming this is bool or should it be string?

i think clearer tables would look something like this (or contain the same information in different format):

Example1

Name	Required	Description	Example
SPEEDTEST_SCHEDULE str	:white_check_mark:	Cron expression used to run speedtests on a scheduled basis. Default: None	1

Example2

Name	Description
SPEEDTEST_SCHEDULE str	Cron expression used to run speedtests on a scheduled basis. Default: None Example: * 1 * * * Required: :white_check_mark:

[alexjustesen]

I agree they need some work, I was targeting re-writing the docs for v1.0.0 so it'll happen at some point this summer.