add script to install lazy.nvim

scripts/install_lazy.nvim

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+set -o errexit
+set -o nounset
+set -o pipefail
+
+LAZY_NVIM_SOURCE="https://github.com/folke/lazy.nvim.git"
+LAZY_NVIM_DESTINATION="${XDG_DATA_HOME}/nvim/lazy/lazy.nvim"
+LAZY_STATE_DIR="${XDG_STATE_HOME}/nvim/lazy"
+
+mkdir -p "${LAZY_STATE_DIR}"
+
+if [ -d "${LAZY_NVIM_DESTINATION}/.git" ]; then
+    echo "INFO: ${LAZY_NVIM_DESTINATION} is already present"
+    exit 0
+fi
+
+echo "INFO: Cloning ${LAZY_NVIM_SOURCE} to ${LAZY_NVIM_DESTINATION}..."
+git clone --filter=blob:none --single-branch "${LAZY_NVIM_SOURCE}" "${LAZY_NVIM_DESTINATION}"