Update TOC in building for linux

docs/building_for_linux.md

@@ -1,28 +1,32 @@
-- [Requirements](#requirements)
-    * [Compiler and Build Essentials](#compiler-and-build-essentials)
-        + [Ubuntu](#ubuntu)
-        + [Arch/Manjaro](#arch-manjaro)
-    * [Qt](#qt)
-        * [Package Manager](#package-manager)
-        + [Ubuntu](#ubuntu-1)
-        + [Arch/Manjaro](#arch-manjaro-1)
-    * [Official Qt Installer](#official-qt-installer)
-    + [`qtchooser`](#-qtchooser-)
-    * [Unofficial Ubuntu Packages](#unofficial-ubuntu-packages)
-    + [Arch/Manjaro](#arch-manjaro-2)
-    * [`qtchooser` and versions](#-qtchooser--and-versions)
-    * [X11](#x11)
-    * [DBUS](#dbus)
-    * [`clang-tidy` and `bear`](#-clang-tidy--and--bear-)
-- [TL;DRs](#tl-drs)
-    * [Ubuntu 16.04 Xenial](#ubuntu-1604-xenial)
-    * [Ubuntu 18.04 Bionic](#ubuntu-1804-bionic)
-    * [Ubuntu 19.04 Disco](#ubuntu-1904-disco)
-    * [Arch/Manjaro](#arch-manjaro-3)
-- [Building](#building)
-- [Configuring](#configuring)
-- [Installing](#installing)
-- [Contributing](#contributing)
+* [Requirements](#requirements)
+  * [Git](#git)
+     * [Ubuntu](#ubuntu)
+     * [Arch/Manjaro](#archmanjaro)
+  * [Compiler and Build Essentials](#compiler-and-build-essentials)
+     * [Ubuntu](#ubuntu-1)
+     * [Arch/Manjaro](#archmanjaro-1)
+  * [Qt](#qt)
+  * [Package Manager](#package-manager)
+     * [Ubuntu](#ubuntu-2)
+     * [Arch/Manjaro](#archmanjaro-2)
+  * [Official Qt Installer](#official-qt-installer)
+     * [qtchooser](#qtchooser)
+  * [Unofficial Ubuntu Packages](#unofficial-ubuntu-packages)
+     * [Arch/Manjaro](#archmanjaro-3)
+  * [qtchooser and versions](#qtchooser-and-versions)
+  * [X11](#x11)
+  * [DBUS](#dbus)
+  * [clang-tidy and bear](#clang-tidy-and-bear)
+* [TL;DRs](#tldrs)
+  * [Ubuntu 16.04 Xenial](#ubuntu-1604-xenial)
+  * [Ubuntu 18.04 Bionic](#ubuntu-1804-bionic)
+  * [Ubuntu 19.04 Disco and newer](#ubuntu-1904-disco-and-newer)
+  * [Arch/Manjaro](#archmanjaro-4)
+* [Building](#building)
+* [Configuring](#configuring)
+* [Installing](#installing)
+* [Contributing](#contributing)
+
 
 Unless you have a good reason not to, just copy and paste the correct TL;DR section into your terminal.