Add install script.

install.sh

@@ -0,0 +1,37 @@
+#!/usr/bin/env bash
+set -e
+
+echo "This script installs Foundation, it is developed against Paper and may depend on"
+echo "Paper-specific features."
+echo
+echo "Installing..."
+
+# Create the plugins directory if it doesn't exist.
+if [ ! -d plugins ]; then
+  echo "Creating plugins directory."
+  mkdir plugins/
+fi
+
+# Base GitLab update manifest.
+base_url="https://git.gorence.io/lgorence/foundation/-/jobs/artifacts/main/raw/"
+query_params="job=build"
+
+# Download the update manifest.
+manifest=$(curl -Ls "$base_url/build/manifests/update.json?$query_params")
+
+# Get plugins list from the manifest.
+plugins=$(echo "$manifest" | jq -r 'keys | .[]')
+
+# Download each plugin from the manifest, can also update plugins.
+for plugin in $plugins
+do
+  # Determine download path, extract version and artifact path URL.
+  dl_path="plugins/$plugin.jar"
+  version=$(echo "$manifest" | jq -r " .[\"$plugin\"].version")
+  artifact_path=$(echo "$manifest" | jq -r " .[\"$plugin\"].artifacts[0]")
+
+  echo "Installing $plugin v$version to $dl_path"
+
+  # Download the plugin and store it at the mentioned path.
+  curl -Ls "$base_url/$artifact_path?$query_params" --output "$dl_path"
+done