Default values of docker env vars are not correct

[sapkra]

In the "Default value" column of the env var table the values are not correct or in some cases even just example values.
I think we should fix the default values and should introduce a new column for examples.

[saghul]

Agreed!

[dj95]

The keys are not 100% correct either. e.g. the google transcription feature in Jigasi requires you to set GOOGLE_APPLICATION_CREDENTIALS in the environment variables (stated out due to logs). However, the jitsi documentation states out, that the credentials need to be set separately as environment variables (e.g. GC_PROJECT_ID) instead of providing a file.