add an installation guide

docs/tutorial/installation.md

@@ -0,0 +1,56 @@
+# Installation
+
+> Tips for installing Electron
+
+To install prebuilt Electron binaries, use [`npm`](https://docs.npmjs.com/).
+The preferred method is to install Electron as a development dependency in your
+app:
+
+```sh
+npm install electron --save-dev --save-exact
+```
+
+The `--save-exact` flag is recommended as Electron does not follow semantic
+versioning. See the
+[versioning doc](https://electron.atom.io/docs/tutorial/electron-versioning/)
+for info on how to manage Electron versions in your apps.
+
+## Global Installation
+
+You can also install the `electron` command globally in your `$PATH`:
+
+```sh
+npm install electron -g
+```
+
+## Customization
+
+If you want to change the architecture that is downloaded (e.g., `ia32` on an
+`x64` machine), you can use the `--arch` flag with npm install or set the
+`npm_config_arch` environment variable:
+
+```shell
+npm install --arch=ia32 electron
+```
+
+## Proxies
+
+If you need to use an HTTP proxy you can [set these environment variables](https://github.com/request/request/tree/f0c4ec061141051988d1216c24936ad2e7d5c45d#controlling-proxy-behaviour-using-environment-variables).
+
+## Troubleshooting
+
+When running `npm install electron`, some users occasionally encounter 
+installation errors.
+
+In almost all cases, these errors are the result of network problems and not 
+actual issues with the `electron` npm package. Errors like `ELIFECYCLE`, 
+`EAI_AGAIN`, `ECONNRESET`, and `ETIMEDOUT` are all indications of such 
+network problems.  The best resolution is to try switching networks, or 
+just wait a bit and try installing again.
+
+You can also attempt to download Electron directly from 
+[electron/electron/releases](https://github.com/electron/electron/releases) 
+if installing via `npm` is failing.
+
+If you need to force a re-download of the asset and the SHASUM file set the
+`force_no_cache` enviroment variable to `true`.