[DOCS] Theengs Plug highlight and SEO improvements (#1730)

* [DOCS] Theengs Plug highlight

* Add alt content for images and description

docs/upload/gitpod.md

@@ -10,9 +10,9 @@ To build OpenMQTTGateway from the web and download the binary, follow these step
 3. A first build for `esp32dev-ble` will be launched automatically. To modify the environment configuration, go to the environments.ini file in the root folder and launch the command like the one shown at the bottom of the image below:
 `platformio run -e <environment name>`
 
-![](../img/OpenMQTTGateway-Build-gitpod-env.png)
+![Gitpod build success](../img/OpenMQTTGateway-Build-gitpod-env.png)
 
 4. Wait for the server to build the binary. Once you see [SUCCESS], you can go to `.pio/build/<environment name>` and download `firmware.bin` and `partitions.bin` by right-clicking on each and selecting "Download."
-![](../img/OpenMQTTGateway-Build-gitpod.png)
+![Gitpod build download](../img/OpenMQTTGateway-Build-gitpod.png)
 
 5. Finally, follow [Option 2](binaries.md) to upload the binary.