docs: corrections and further clarifications

- (correction) removed comments from code samples.
-(correction) remove recommendation for global
install on CI environemnts.
- Synched README.md and SUMMARY.md

docs/03-recipes/ci-pipelines-recipes.md

@@ -1,4 +1,4 @@
-# CI configurations
+# CI pipelines recipes
 - [CircleCI 2.0 workflows](circleci-workflows.md)
 - [Travis CI](travis.md)
 - [GitLab CI](gitlab-ci.md)

docs/03-recipes/git-hosted-services.md

@@ -1,12 +1,2 @@
-# Recipes
-
-## CI configurations
-- [CircleCI 2.0 workflows](circleci-workflows.md)
-- [Travis CI](travis.md)
-- [GitLab CI](gitlab-ci.md)
-
-## Git hosted services
+# Git hosted services
 - [Git authentication with SSH keys](git-auth-ssh-keys.md)
-
-## Package managers and languages (to be completed)
-