Add npm cheatsheet

cheat/cheatsheets/npm

@@ -0,0 +1,22 @@
+# Every command shown here can be used with the `-g` switch for global scope
+
+# Install a package in the current directory
+npm install <package>
+
+# Install a package, and save it in the `dependencies` section of `package.json`
+npm install --save <package>
+
+# Install a package, and save it in the `devDependencies` section of `package.json`
+npm install --save-dev <package>
+
+# Show outdated packages in the current directory
+npm outdated
+
+# Update outdated packages
+npm update
+
+# Update `npm` (will override the one shipped with Node.js)
+npm install -g npm
+
+# Uninstall a package
+npm unintall <package>