docs: add installation instructions

Author: nik-rev

.github/workflows/gh-pages.yml

@@ -29,7 +29,7 @@ jobs:
       - name: Upload GitHub Pages artifact
         uses: actions/upload-pages-artifact@v3
         with:
-          path: docs
+          path: .
 
   deploy:
     runs-on: ubuntu-latest

docs/src/SUMMARY.md

@@ -1,3 +1,3 @@
 # Summary
 
-- [Chapter 1](./chapter_1.md)
+- [Installation](./installation.md.md)

docs/src/chapter_1.md

@@ -0,0 +1,38 @@
+# Installation
+
+## Homebrew
+
+```sh
+brew install nik-rev/tap/ferrishot
+```
+
+## PowerShell
+
+```sh
+powershell -ExecutionPolicy Bypass -c "irm https://github.com/nik-rev/ferrishot/releases/latest/download/ferrishot-installer.ps1 | iex"
+```
+
+## Shell
+
+```sh
+curl --proto '=https' --tlsv1.2 -LsSf https://github.com/nik-rev/ferrishot/releases/latest/download/ferrishot-installer.sh | sh
+```
+
+## Nix
+
+Add it to your `flake.nix`:
+
+```nix
+# add it to your inputs
+inputs.ferrishot.url = "github:nik-rev/ferrishot/main";
+# then use it in home-manager for example
+inputs.ferrishot.packages.${pkgs.system}.default
+```
+
+## Cargo
+
+If you use Linux, see [`CONTRIBUTING.md`](./CONTRIBUTING.md) for details on which dependencies you will need.
+
+```sh
+cargo install ferrishot
+```