Added triggers.yml comments

Author: michalChrobot

.yamato/_triggers.yml

@@ -1,6 +1,44 @@
-{% metadata_file .yamato/project.metafile %}
+{% metadata_file .yamato/project.metafile %} # All configuration that is used to create different configurations (used in for loops) is taken from this file.
 ---
 
+# DESCRIPTION--------------------------------------------------------------------------
+# This configuration defines three main CI trigger patterns:
+# 1. Pull Request Validation: Validation performed on PR basis
+# 2. Nightly Development: Test set run nightly (validates most important test cases)
+# 3. Weekly Full Validation: Test set run weekly (validates all test cases to prevent any surprises)
+# Each pattern represents different balance between validation depth, execution time and CI resource usage
+
+# TRIGGER PATTERNS-------------------------------------------------------------------
+# Pull Request:
+# This test validates Standards, Package tests, Project tests and Desktop standalone tests to ensure that main platforms are covered
+# Triggers on PRs to develop, develop, and release branches
+# Focuses on critical validation paths that we should validate before merging PRs
+# Cancels previous runs on new commits
+# Excludes draft PRs
+
+# Nightly:
+# This test validates same subset as pull_request_trigger with addition of mobile/console tests and webgl builds
+# Runs daily on develop (local configuration)
+# Includes all test types but only on trunk.
+# Adds platform-specific and APV validation
+
+# Weekly:
+# This test validates same subset as develop_nightly but runs per all supported editors as well as executes code coverage test and runs project standards per project
+# Runs across all supported editor versions
+# Includes code coverage analysis
+# Validates all projects and standards
+
+# CONFIGURATION STRUCTURE--------------------------------------------------------------
+# Jobs configurations are generated by ensuring that all dependencies are successful.
+# The dependencies are taken from _run-all.yml file where we can gather multiple tests into proper sets
+
+# QUALITY CONSIDERATIONS---------------------------------------------------------------
+# It's important to ensure that all dependencies exist (this can be verified in Yamato) since a modification in parameters may result in a given job not being generated, and thus we will not be able to run such erroneous job.
+
+
+
+#-----------------------------------------------------------------------------------
+
 # Run all relevant tasks when a pull request targeting the develop or release branch is created or updated.
 pull_request_trigger:
   name: Pull Request Trigger (develop, develop-2.0.0, & release branches)