Add Uptime-Kuma introduction, write descriptive alt text site-wide, and fix brand capitalization and filenames with spaces

content/en/3.serveex/2.core/2.docker.md

@@ -12,7 +12,7 @@ A **container** sidesteps the problem: it packages an app together with everythi
 
 **Docker** is the tool that builds, starts and manages these containers. Point it at an *image*, a ready-made snapshot of an app maintained by its developers, and it downloads it and runs it in one command. The rest of Serveex is built entirely on it: every app from here on is one Docker container, or a handful of them working together.
 
-![picture](/img/serveex/docker.svg)
+![Diagram of Docker containers running isolated from the host system](/img/serveex/docker.svg)
 
 ## Install Docker
 ::steps{level="3"}
@@ -53,7 +53,7 @@ sudo mkdir /srv/docker
 ## Install [Dockge](https://github.com/louislam/dockge) to manage and deploy containers
 [Dockge](https://github.com/louislam/dockge) is a web tool to create, configure, launch, and manage Docker containers. It's a simple, intuitive interface that’s lighter and easier for beginners than using the CLI or Portainer.
 
-![picture](/img/serveex/dockge.png)
+![Dockge web interface for managing Docker Compose stacks](/img/serveex/dockge.png)
 
 ### Configuration