Fixes, failback procedure and notes in README.md

2 jobs for database_wrangler_master in 19 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Test
failed #2723820
references

00:00:11

passed #2723819
shellcheck

00:00:19

 
Name Stage Failure
failed
references Test
+ [[ -x /builds/gitlab-com/migration/bin/scripts/02_failover/060_go/p04/073-check-pgbouncer-node-in-gcp.sh ]]
+ IFS=
+ read -r file
+ [[ -f /builds/gitlab-com/migration/bin/scripts/02_failover/060_go/p04/074-convert-azure-master-to-gcp-standby.sh ]]
+ echo 'bin/scripts/02_failover/060_go/p04/074-convert-azure-master-to-gcp-standby.sh is missing or not executable'
bin/scripts/02_failover/060_go/p04/074-convert-azure-master-to-gcp-standby.sh is missing or not executable
+ grep -En bin/scripts/02_failover/060_go/p04/074-convert-azure-master-to-gcp-standby.sh '/builds/gitlab-com/migration/.gitlab/issue_templates/*.md'
grep: /builds/gitlab-com/migration/.gitlab/issue_templates/*.md: No such file or directory
ERROR: Job failed: exit code 2