feat(nvm): speed up nvm startup by enabling lazy loading

omz-custom/nvm.sh

@@ -0,0 +1,10 @@
+# NVM lazy loading (speeds up shell startup significantly)
+export NVM_DIR="$HOME/.nvm"
+nvm() {
+  unset -f nvm node npm npx
+  [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"
+  nvm "$@"
+}
+node() { nvm; unset -f node; node "$@"; }
+npm() { nvm; unset -f npm; npm "$@"; }
+npx() { nvm; unset -f npx; npx "$@"; }