#326 updated readme to explain the usage of SITECORE_LICENSE_LOCATION in 9.3 docker images (#327)

Co-authored-by: Rey Rahadian <rey.rahadian@akqa.com>

Author: reyrahadian

README.md

@@ -69,6 +69,8 @@ When completed then...
 1. Run `Set-LicenseEnvironmentVariable.ps1 -Path C:\license\license.xml` (use the `PersistForCurrentUser` switch to persist the license for future sessions). This will gzip and base64 encode the license file content and save it in `$env:SITECORE_LICENSE`.
 1. Switch directory to `.\windows\tests\9.3.x\` and then run any of the docker-compose files, for example an XM with: `docker-compose --file .\docker-compose.xm.yml up`
 
+9.3 docker images still supports mounting the license file inside the container, if for some reason you need to use this method please see [License file volume mount configuration for 9.3 docker images](#license-file-volume-mount-configuration-for-9.3-docker-images)
+
 **For Sitecore 9.2.x:**
 
 1. Place your Sitecore license file at `C:\license\license.xml`, or override location using the environment variable `LICENSE_PATH` like so: `$env:LICENSE_PATH="D:\my\sitecore\licenses"`
@@ -251,6 +253,37 @@ SitecoreImageBuilder\Invoke-Build `
 
 ```
 
+### License file volume mount configuration for 9.3 docker images
+
+If you've been using the license file mounted approach in 9.2 docker images, you can still continue using the same approach in 9.3 docker images. Follow these steps
+
+1. Place your Sitecore license file at `C:\license\license.xml`, or override location using the environment variable `LICENSE_PATH` like so: `$env:LICENSE_PATH="D:\my\sitecore\licenses"`
+1. Switch directory to `.\windows\tests\9.3.x\`  and then run any of the docker-compose files, for example an XM with: `docker-compose --file .\docker-compose.xm.yml up` after the docker compose file has been updated following the instruction below
+
+#### For cm and cd
+1. Add a new volume mount configuration using the environment variable `LICENSE_PATH` to a folder inside the container, for example `C:\license`
+1. Add a new environment variable `SITECORE_LICENSE_LOCATION` that point to the license file path inside the container, for example: `C:\license\license.xml`
+
+```
+cm:
+  environment:
+    SITECORE_LICENSE_LOCATION: C:\license\license.xml
+  volumes:
+    - ${LICENSE_PATH}:C:\license
+```
+
+#### For xconnect, xconnect-automationengine, xconnect-indexworker, xconnect-processingengine
+1. Add a new volume mount configuration using the environment variable `LICENSE_PATH` to a folder inside the container, for example `C:\license`
+1. Add a new environment variable `SITECORE_LICENSE_LOCATION` that point to the license file folder path inside the container, for example: `C:\license`
+
+```
+xconnect:
+  environment:
+    SITECORE_LICENSE_LOCATION: C:\license
+  volumes:
+    - ${LICENSE_PATH}:C:\license
+```
+
 ## Cleanup
 
 Its recommended to clean up you Docker engine hosts (developer workstations, build agents etc.) regularly.