content: finished bash, started git

also some minor style improvements

Author: debel

src/content/lessons/exercise1.md

@@ -0,0 +1,34 @@
+---
+title: 'Intro to git'
+description: 'An overview of what git is, how it works and why we want to learn to use it'
+order: 3
+tags: ['intro', 'git']
+---
+
+## Git
+
+Git is the most popular **version control system** in the world.
+
+<bonus-content>
+
+It was published by the creator of Linux - Linus Torvalds in 2005.
+
+</bonus-content>
+
+It is used for both corporate, open-source and hobby projects.
+
+> _Did you know_: The german government publishes their [constitution](https://github.com/bundestag/gesetze) on GitHub?
+
+---
+
+## What is version control?
+
+---
+
+## Hello git
+
+```bash
+mkdir my-first-git-project
+cd my-first-git-project
+git init
+```

src/content/lessons/intro-to-git.md

@@ -29,3 +29,37 @@ Bash processes commands in this order:
 ---
 
 > __Did you know:__ there is a version of the popular containerization tool Docker [written entirely in bash](https://github.com/p8952/bocker)
+
+<bonus-content>
+
+## Overview of the common top-level directories
+
+> In UNIX-like system everything is represented as a file
+
+```bash
+/     # root - the top level directory
+/bin/     # holds common programs accessible by all users
+/boot/    # contains files needed to start the system
+/dev/     # contains device files
+/etc/     # contains system configuration files
+/home/    # each user has their own directory under /home/{user-name}
+/media/   # usually where external storage is mounted
+/mnt/     # used for manually mounting external storage
+/lib/     # contains shared libraries
+```
+
+---
+
+```bash
+/opt/     # usually holds programs built locally from source
+/root/    # the home directory of the root user
+/sbin/    # contains programs only accessible to the root user
+/sys/     # contains files representing devices
+/tmp/     # contains temporary files
+/usr/     # holds a mish-mash of programs, libraries, docs and more
+/var/     # usually contains logs and other semi-temporary data
+```
+
+> There are a lot of details and specifics of different UNIX variants that we would not have time to explore in depth.
+
+</bonus-content>