feat(docs/readme.md): move installation section from readme to specific file

docs/README.md

@@ -0,0 +1,77 @@
+# Installing
+
+To host LibreY using Docker, you can follow the instructions in the [Docker directory](https://github.com/Ahwxorg/LibreY/tree/main/docker).
+
+To host LibreY using your OS's native package manager and PHP+NGINX, you can use the following steps as a guide.
+
+These instructions are specific to Debian GNU/Linux but should be similar on most *nix variants (differences may include commands for package management, init system, php-fpm.sock location and availability of fastcgi-php.conf)
+
+Install the packages (Debian GNU/Linux):
+
+```sh
+apt install php php-fpm php-dom php-curl php-apcu nginx git
+```
+
+Install the packages (Arch Linux):
+```sh
+pacman -S php php-fpm php-apcu nginx git
+```
+
+Clone LibreY:
+
+```sh
+mkdir -p /var/www/html
+git clone https://github.com/Ahwxorg/LibreY.git /var/www/html/LibreY
+```
+
+Rename the config and opensearch files, edit manually if needed:
+
+```sh
+cd /var/www/html/LibreY/
+mv config.php.example config.php
+mv opensearch.xml.example opensearch.xml
+```
+
+Change opensearch.xml to point to your domain:
+
+```sh
+sed -i 's/http:\/\/localhost:80/https:\/\/your.domain/g' opensearch.xml
+```
+
+An nginx configuration similar to the one below should be placed in your `http { ... }` block or a file that is automatically detected as such.
+
+```sh
+server {
+        listen 80;
+
+        server_name your.domain;
+
+        root /var/www/html/LibreY;
+        index index.php;
+
+        location ~ \.php$ {
+               include snippets/fastcgi-php.conf;
+               fastcgi_pass unix:/run/php/php-fpm.sock;
+        }
+}
+```
+
+You can optionally remove the .php extension in URLs by adding this code your `server { ... }` block.
+
+```sh
+location / {
+       try_files $uri $uri/ @extensionless-php;
+}
+
+location @extensionless-php {
+       rewrite ^(.*)$ $1.php last;
+}
+```
+
+Start php-fpm and nginx immediately and on every boot:
+
+```sh
+systemctl enable --now php-fpm nginx
+```
+
+Now LibreY should be running at the port you specified!