Updated install instructions

I updated the install instructions (snap, scoop, chocolatey) and added the ones where Gutenberg already got renamed to Zola also to the top of the document.

Should yaourt be replaced by one of the other aur-helpers (pikaur, yay,...) as the development for it is stalled/discontinued for quite some time now although it is still working?

Scoop: https://github.com/lukesampson/scoop/blob/master/bucket/zola.json
Chocolatey: https://chocolatey.org/packages/zola
Snap: https://snapcraft.io/zola

docs/content/documentation/getting-started/installation.md

@@ -6,6 +6,8 @@ weight = 1
 Zola provides pre-built binaries for MacOS, Linux and Windows on the
 [GitHub release page](https://github.com/getzola/zola/releases).
 
+## Linux
+
 ## Arch Linux
 
 Use your favourite AUR helper to install the `zola-bin` package.
@@ -14,6 +16,28 @@ Use your favourite AUR helper to install the `zola-bin` package.
 $ yaourt -S zola-bin
 ```
 
+### Snapcraft
+
+Zola is available on snapcraft:
+
+```bash
+$ snap install --edge zola
+```
+
+## Windows
+
+Zola is available on [Scoop](http://scoop.sh):
+
+```bash
+$ scoop install zola
+```
+
+And [Chocolatey](https://chocolatey.org/):
+
+```bash
+$ choco install zola
+```
+
 ## From source
 To build it from source, you will need to have Git, [Rust (at least 1.28) and Cargo](https://www.rust-lang.org/)
 installed. You will also need additional dependencies to compile [libsass](https://github.com/sass/libsass):