Added docs on testing new changes locally

src/SUMMARY.md

@@ -40,4 +40,5 @@
     - [New API Scanner](./new-scanner-integrations/new-scanner-integration-api.md)
     - [Add scanner to config file](./new-scanner-integrations/command-config-file.md)
     - [Install instructions in DockerFile](./new-scanner-integrations/command-docker-file.md)
-
+- [🔎 Testing new changes](./testing-new-changes/testing.md)
+    - [Building containers locally](./testing-new-changes/building-containers-locally.md)

src/testing-new-changes/building-containers-locally.md

@@ -0,0 +1,24 @@
+# Building containers locally
+
+By default, Mantis Docker setup pulls Mantis container from Github Container Registry. To test the changes you made locally, you need to build the mantis docker container locally. 
+
+To achieve this, in your `setup/docker/docker-compose.yml` uncomment the following lines and comment the "image" directive.
+
+```yaml
+#build:
+#  dockerfile: Dockerfile
+#  context: ../../
+```
+
+Final mantis container block would look like, 
+
+```yaml
+mantis:
+  build:
+    dockerfile: Dockerfile
+    context: ../../
+#image: ghcr.io/phonepe/mantis:latest
+... snipped ...
+```
+
+Now your mantis container is built locally and you can test your changes.

src/testing-new-changes/testing.md

@@ -0,0 +1,3 @@
+# Testing new changes
+
+This section covers testing new changes locally.