docs: add commands for setting up and testing various examples (#16)

Author: zimeg

.github/MAINTAINERS_GUIDE.md

@@ -1,7 +1,11 @@
-# Maintainers guide
+# Maintainers Guide
 
 Let's hope to have matching examples of documentation and reference for various runtimes be consistent!
 
+- **[Development](#development)**: Making changes alongside the Java Slack SDK.
+- **[Commands](#commands)**: Reference to running example code of this project.
+- **[Structure](#structure)**: Adding examples for features of the Slack Platform.
+
 ## Development
 
 Bringing ongoing changes from the [Java Slack SDK](https://github.com/slackapi/java-slack-sdk) requires [building from source](https://docs.slack.dev/tools/java-slack-sdk/guides/web-api-client-setup#build-from-source) with these commands:
@@ -12,7 +16,14 @@ $ cd java-slack-sdk
 $ mvn install -Dmaven.test.skip=true
 ```
 
-This adds a snapshot to the `$HOME/.m2` path that are used after updating the versions found in a `pom.xml` file.
+This adds a snapshot to the `$HOME/.m2` path that are used after updating the versions found in a `pom.xml` file:
+
+```sh
+$ git clone [email protected]:slack-samples/bolt-java-examples.git
+$ cd bolt-java-examples
+$ cd block-kit  # Navigate to whatever example
+$ vim pom.xml
+```
 
 ```diff
     <dependency>
@@ -22,3 +33,33 @@ This adds a snapshot to the `$HOME/.m2` path that are used after updating the ve
 +     <version>1.45.4-SNAPSHOT</version>
     </dependency>
 ```
+
+## Commands
+
+Each example has matching commands to run tests:
+
+```sh
+$ mvn --batch-mode spotless:check
+$ mvn --batch-mode test -Dspotless.apply.skip
+```
+
+## Structure
+
+New code snippets or samples added should match the structure of the [docs.slack.dev](https://docs.slack.dev) site:
+
+```txt
+|- .github
+   |- dependabot.yml  # https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/controlling-dependencies-updated#defining-multiple-locations-for-manifest-files
+|- block-kit
+   |- blocks          # https://docs.slack.dev/reference/block-kit/blocks
+   |- formatting      # https://docs.slack.dev/block-kit/formatting-with-rich-text
+|- messaging
+   |- sending         # https://docs.slack.dev/messaging/sending-and-scheduling-messages
+   |- work-objects    # https://docs.slack.dev/messaging/work-objects
+```
+
+Some pages might reference distinct examples needing unique app manifests. These should appear in separate nested directories for a minimal demonstration.
+
+Certain features or demonstrations might not have a clear example on the docs site. Discussions with the kind documentation team ought be started if so! We hope folks find relevant examples through those pages.
+
+A goal of this project is to be a source of tested reference.