SDK-4093. Added Security update checker doc

docs/scos/dev/guidelines/keeping-a-project-upgradable/upgradability-guidelines/security-update.md

@@ -0,0 +1,44 @@
+---
+title: Security update checker
+description: Reference information for evaluator tools.
+template: howto-guide-template
+---
+
+Security Update Checker is a tool that checks if security fixes exist for Spryker modules that are present in your project.
+
+## Problem description
+
+A project can sometimes use dependencies that contain known vulnerabilities. To minimize the security risk for the project, such dependencies should be updated to the version that has the vulnerability fixed.
+
+## Example of an evaluator error message
+
+```bash
+=======================
+SECURITY UPDATE CHECKER
+=======================
+
+Message: Security update available for the module spryker/price-product-merchant-relationship-storage, actual version 1.14.0
+Target:  spryker/price-product-merchant-relationship-storage:1.15.0
+```
+
+## Example of code that causes an evaluator error
+
+Your `composer.lock` file contains package versions that have security issues:
+
+```bash
+...
+{
+    "name": "spryker/price-product-merchant-relationship-storage",
+    "version": "1.14.0",
+    "source": {
+        "type": "git",
+        "url": "https://github.com/spryker/price-product-merchant-relationship-storage.git",
+        ...
+    },
+    ...
+````
+
+### Resolving the error
+
+To resolve the error:
+1. Upgrade the package to a version where the vulnerability issue is fixed.