Minor extension docs improvement (#16516)

* Minor extension docs improvement

Signed-off-by: Guillaume Tardif <guillaume.tardif@gmail.com>

* Apply suggestions from code review

Co-authored-by: Lucas Bernalte <lucas.bernalte@gmail.com>

* Update desktop/extensions-sdk/build/frontend-extension-tutorial.md

Co-authored-by: Allie Sadler <102604716+aevesdocker@users.noreply.github.com>

Signed-off-by: Guillaume Tardif <guillaume.tardif@gmail.com>
Co-authored-by: Lucas Bernalte <lucas.bernalte@gmail.com>
Co-authored-by: Allie Sadler <102604716+aevesdocker@users.noreply.github.com>

desktop/extensions-sdk/build/backend-extension-tutorial.md

@@ -17,7 +17,7 @@ why and how to add a backend.
 
 > Note
 >
-> If you want to start a codebase for your new extension, our [Quickstart guide](../quickstart.md) and `docker extension init <my-extension>` provides a better base for your extension as it is more up-to-date and related to your install of Docker Desktop.
+> Check the [Quickstart guide](../quickstart.md) and `docker extension init <my-extension>`. They provide a better base for your extension as it's more up-to-date and related to your install of Docker Desktop.
 
 ## Why add a backend?
 

desktop/extensions-sdk/build/frontend-extension-tutorial.md

@@ -92,7 +92,7 @@ FROM alpine
 LABEL org.opencontainers.image.title="My extension" \
     org.opencontainers.image.description="Your Desktop Extension Description" \
     org.opencontainers.image.vendor="Awesome Inc." \
-    com.docker.desktop.extension.api.version="0.3.0" \
+    com.docker.desktop.extension.api.version="0.3.3" \
     com.docker.desktop.extension.icon="https://www.docker.com/wp-content/uploads/2022/03/Moby-logo.png" \
     com.docker.extension.screenshots="" \
     com.docker.extension.detailed-description="" \
@@ -142,6 +142,10 @@ COPY --from=client-builder /ui/build ui
   </div>
 </div>
 
+> Note
+>
+> In the example Dockerfile, you can see that the image label `com.docker.desktop.extension.icon` is set to an icon URL. The Extensions Marketplace displays this icon without installing the extension. The Dockerfile also includes `COPY docker.svg .` to copy an icon file inside the image. This second icon file is used to display the extension UI in the Dashboard, once the extension is installed.
+
 ## Configure the metadata file
 
 In order to add a tab in Docker Desktop for your extension, you have to configure it in the `metadata.json`

desktop/extensions-sdk/build/minimal-frontend-extension.md

@@ -40,7 +40,7 @@ Although you can start from an empty directory, it is highly recommended that yo
 
 At a minimum, your Dockerfile needs:
 
-- Labels which provide extra information about the extension.
+- [Labels](../extensions/labels.md) which provide extra information about the extension, icon and screenshots.
 - The source code which in this case is an `index.html` that sits within the `ui` folder.
 - The `metadata.json` file.
 
@@ -51,7 +51,7 @@ FROM scratch
 LABEL org.opencontainers.image.title="Minimal frontend" \
     org.opencontainers.image.description="A sample extension to show how easy it's to get started with Desktop Extensions." \
     org.opencontainers.image.vendor="Awesome Inc." \
-    com.docker.desktop.extension.api.version="0.3.0" \
+    com.docker.desktop.extension.api.version="0.3.3" \
     com.docker.desktop.extension.icon="https://www.docker.com/wp-content/uploads/2022/03/Moby-logo.png"
 
 COPY ui ./ui

desktop/extensions-sdk/extensions/multi-arch.md

@@ -93,7 +93,7 @@ FROM alpine
 LABEL org.opencontainers.image.title="example-extension" \
     org.opencontainers.image.description="My Example Extension" \
     org.opencontainers.image.vendor="Docker Inc." \
-    com.docker.desktop.extension.api.version=">= 0.1.0"
+    com.docker.desktop.extension.api.version=">= 0.3.3"
 
 COPY --from=dl /out /
 ```