fix lack of sql engine environment variable

[damonmcc]

resolved #259

issues

• python code expects a .env file to exists to get environment variables
• apparently, these must be declared in the dokku instance (digital ocean droplet) and can't really be passed as repo secrets through the github action which deploys the app

changes

• manually added new environment variable in dokku instance
• added instructions to do that in the readme
• increased the timeout for getting sql dump files (timed out while getting dof files)
• use expanders for certain page sections to improve usability
• other readme improvements

tests

• live QAQC app which was deployed from this branch
• screenshot of ZTL source QAQC showing that the SQL connection is working now
  • 
• screenshot of sections using new expanders (while they're collapsed by default)
  • 

[fvankrieken]

lgtm - you adding anything else, or do you want anything explicitly tested?

[damonmcc]

@fvankrieken nothing to add. for testing: no new functions here so I didn't add new tests and the deployed app is using these changes if you wanna check em out

[fvankrieken]

@fvankrieken nothing to add. for testing: no new functions here so I didn't add new tests and the deployed app is using these changes if you wanna check em out

I meant tested by me! Good to merge

[mbh329]

app looks good and everything ran as expected