Docs: add set up walkthrough

docs/set-up-walkthrough.md

@@ -0,0 +1,43 @@
+# Set Up (Walkthrough)
+
+1. Install [PlatformIO](https://platformio.org/) or use their [VS Code extension](https://marketplace.visualstudio.com/items?itemName=platformio.platformio-ide)
+    - The extension will automatically install various dependencies (such as the necessary compilers). Be sure to reload the VS Code window according to the prompts.
+    - After installation, follow their [Quick Start guide](https://docs.platformio.org/en/latest/integration/ide/vscode.html#quick-start) to deploy an example program to your ESP8266.
+    - **You need to make sure that building and deploying programs to your ESP8266 is working before continuing with this guide.**
+
+2. Clone this repository, and `cd` into the directory
+    - Note: if you plan to contribute changes, it'll be easier to fork this repo first, then clone your fork.
+
+```
+  $ git clone git@github.com:maakbaas/esp8266-iot-framework.git
+  $ cd esp8266-iot-framework
+```
+
+3. Update the PlatformIO configuration for your specific ESP8266 board
+    - You should do this by directly editing `platformio.ini` rather than using the VS Code extension to add a configuration. This is because by default, saving a change via the PlatformIO UI will overwrite the entire config file, and the custom configuration presently there will be lost.
+    - If you followed the Quick Start guide from Step 1 above, a `platformio.ini` will have been created with your device info. You can copy/paste that info into this project's `platformio.ini` instead.
+
+3. In `platformio.ini`, comment out everything related to `extra_scripts`
+    - The output those scripts generate is committed to this repo, so you only need to uncomment those lines if you want to rebuild this project from source. Review [Getting Started](getting-started.md) for details.
+    - For example, the config for a Wemos D1 Mini would look like:
+
+```diff
+# platformio.ini
+-[env:nodemcuv2]
++[env:d1_mini]
+ platform = espressif8266
+-board = nodemcuv2
++board = d1_mini
+```
+
+4. Run the `PlatformIO: Build` task. It should finish successfully.
+
+5. Run the `PlatformIO: Upload` task.
+    - Don't forget to plug your ESP8266 device into your computer first :)
+
+6. Your ESP8266 is now running a Wifi captive portal with the SSID `Generic ESP8266 Firmware`
+    - Join that network, and then navigate to `192.168.4.1` in a web browser.
+    - The captive portal page should load.
+
+7. Congrats! You have successfully built and deployed the ESP8266 IoT Framework
+    - Read the other documentation materials to see what you can do.