Documentation: Add MD version of webinar

Adds a slightly cleaned up version of the quick start guide
webinar section 1 as a quick start guide. The old quick start
is quite out of date, we should consider removing that and using
this as a replacement.

NOTE: Still need to hook in the indexes, and determin what to do
with the current quick start file (move this and replace?)

docs/getting_started/first_example.md

@@ -0,0 +1,123 @@
+# An SDK example
+
+The SDK provides a number of example devices and controllers that can be used to
+familiarize yourself with the SDK and the Matter ecosystem.
+
+## Example Devices
+
+The example devices (occasionally referred to as "apps") are located in the
+[examples](../../examples/) directory. The examples often implement one
+particular device type. Some have implementations for various platforms.
+
+The linux platform examples are provided as examples, and are used in the CI.
+These can be used for preliminary testing.
+
+The all-clusters-app is used by the QA team for testing. This app implements
+nearly all the available clusters and does not conform to a specific device
+type. This app is not a good starting place for product development.
+
+## Example Controllers
+
+The SDK has two example controllers that can be used to interact with devices
+for testing.
+
+[chip-tool](../../examples/chip-tool/) is a C++ command line controller with an
+interactive shell. More information on chip-tool can be found in the
+[chip-tool guide](../guides/chip_tool_guide.md).
+
+[chip-repl](../../src/controller/python/chip-repl.py) is a shell for the python
+controller. The chip-repl is part of the python controller framework, often used
+for testing. More information about the python controller can be found in the
+[python testing](../testing/python.md) documentation.
+
+## Building your first demo app (lighting)
+
+The examples directory contains a set of apps using an example device
+composition \.zap file. (For more information about device composition and zap,
+see [ZAP documentation](../getting_started/zap.md)).
+
+This quick start guide will walk you through
+
+-   Building an app (lighting app) for the host platform
+-   Interacting with the app using chip\-tool \(controller\)
+
+### Building the lighting app
+
+-   Install prerequisites from docs/guides/BUILDING\.md
+-   Run bootstrap or activate to install all the required tools etc.
+    -   `. scripts/bootstrap.sh` \- run this first\, or if builds fail
+    -   `. scripts/activate.sh` \- faster\, use if you’ve already bootstrapped
+        and are just starting a new terminal
+
+The build system we use is Ninja / GN. You can use a standard gn gen / ninja to
+build as normal, or use the scripts to build specific variants. More information
+about the build system can be found at [BUILDING.md](../guides/BUILDING.md). The
+official quickstart guide for the build system is located ag
+https://gn.googlesource.com/gn/+/master/docs/quick_start.md and a full reference
+can be found at https://gn.googlesource.com/gn/+/main/docs/reference.md.
+
+To build with the scripts, use scripts/build/build_examples\.py -
+`scripts/build/build_examples.py targets` -
+`scripts/build/build_examples.py --target <your target> build` - builds to
+`out/<target_name>/`
+
+Scripts can be used to build both the lighting app and chip tool
+
+-   Lighting app \(device\)
+    -   `./scripts/build/build_examples.py --target linux-x64-light-no-ble build`
+    -   This will build an executable to
+        `./out/linux-x64-light-no-ble/chip-lighting-app`
+
+*   NOTE that the host name (linux-x64 here) may be different on different
+    systems ex. darwin
+
+-   chip-tool (controller)
+    -   `./scripts/build/build_examples.py --target linux-x64-chip-tool build`
+    -   This will build an executable to `./out/linux-x64-chip-tool/chip-tool`
+
+### Building / Interacting with Matter Examples
+
+The first thing you need to do is to commission the device. First start up the
+app in one terminal. By default it will start up with the default discriminator
+(3840) and passcode (20202021) and save its non-volatile information in a KVS in
+/temp/chip_kvs. You can change these, and multiple other options on the command
+line. For a full description, use the `--help` command.
+
+Start the lighting app in one terminal using
+
+`./out/linux-x64-light-no-ble/chip-lighting-app`
+
+The lighting app will print out all its setup information. You can get the setup
+codes, discriminator and passcode from the logs.
+
+Open a new terminal to use chip tool. Commission the device using:
+
+`./out/linux-x64-chip-tool/chip-tool pairing code 0x12344321 MT:-24J0AFN00KA0648G0`
+
+NOTE: pairing is the old name for commissioning. 0x12344321 is the node ID you
+want to assign to the node. 0x12344321 is the default for testing.
+MT:-24J0AFN00KA0648G0 is the QR code for a device with the default discriminator
+and passcode. If you have changed these, the code will be different.
+
+#### Basic device interactions - Sending a command
+
+`./chip-tool onoff on 0x12344321 1`
+
+where:
+
+-   onoff is the cluster name
+-   on is the command name
+-   0x12344321 is the node ID you used for commissioning
+-   1 is the endpoint
+
+#### Basic device interactions - Reading an attribute
+
+`./chip-tool onoff read on-off 0x12344321 1`
+
+where:
+
+-   onoff is the cluster name
+-   read is the desired action
+-   on is the attribute name
+-   0x12344321 is the node ID you used for commissioning
+-   1 is the endpoint