Update GCP docs #123

coverage

File	Coverage
All files	`86%`	✅
base.py	`91%`	✅
exc.py	`57%`	✅
hpc.py	`78%`	✅
local.py	`70%`	✅
postprocessing.py	`84%`	✅
utils.py	`91%`	✅
cloud/docker_base.py	`78%`	✅
sampler/base.py	`79%`	✅
sampler/downselect.py	`33%`	✅
sampler/precomputed.py	`93%`	✅
sampler/residential_quota.py	`61%`	✅
test/shared_testing_stuff.py	`85%`	✅
test/test_docker.py	`33%`	✅
test/test_local.py	`97%`	✅
test/test_validation.py	`97%`	✅
workflow_generator/base.py	`90%`	✅
workflow_generator/commercial.py	`53%`	✅
workflow_generator/residential_hpxml.py	`86%`	✅

Minimum allowed coverage is 33%

Generated by 🐒 cobertura-action against 400accc