doc: PYEUDIW_LRU_CACHE_TTL

[peppelinux]

here https://github.com/italia/eudi-wallet-it-python/pull/292/files#diff-b05fcae9a8c216be8e27cab696d1cedbbcb1bd2b5e72417b2434745fa638960bR252

we need to add into the documentation the meaning about how to use the env variables

[LadyCodesItBetter]

@peppelinux Just this variable? Or the entire env set?

[peppelinux]

ok, let's rescope it, please all the getenv statements i nthe code containing the env variable used, must be documented in a specific table here:

https://github.com/italia/eudi-wallet-it-python/blob/dev/README.SATOSA.md

[peppelinux]

part of them are here:

eudi-wallet-it-python/docs/TRUST.md

Line 28 in 68246ab

Some HTTPC parameters are commonly used, have a default value and as an alternative can be optionally defined by an environment variable.

while the http client is not only related to the trust component, therefore I'd suggest to creare a separate documentation for all the ENV vars @LadyCodesItBetter

[peppelinux]

another one is here:

eudi-wallet-it-python/example/satosa/integration_test/README.md

Line 18 in 68246ab

The MongoDB connection is configured dynamically using the environment variable `PYEUDIW_MONGO_TEST_AUTH_INLINE`.

[peppelinux]

Resolved by #323