add getting started page; enable higlightjs

doc/services-flake.yaml

@@ -3,6 +3,8 @@
 
 page:
   siteTitle: services-flake
+  headHtml: |
+    <snippet var="js.highlightjs" />
 
 template:
   # You can add your own variables here, like editBaseUrl.

doc/services-flake/services.md

@@ -0,0 +1,20 @@
+---
+short-title: Services
+---
+
+# Supported services
+
+>[!warning]
+> This list denotes the progress of documentation, not implementation. See full list of implemented services at [gh].
+
+- [ ] Apache Kafka
+- [ ] Elasticsearch
+- [ ] MySQL
+- [ ] Nginx
+- [ ] PostgreSQL
+- [ ] Redis
+- [ ] Redis Cluster
+- [ ] Zookeeper
+- [ ] ...
+
+[gh]: https://github.com/juspay/services-flake

doc/services-flake/start.md

@@ -0,0 +1,60 @@
+---
+order: -10
+---
+
+# Getting started
+
+
+## New project
+
+Use the [template flake](https://github.com/juspay/services-flake/blob/main/example/flake.nix) provided by `services-flake`:
+```sh
+mkdir example && cd ./example
+nix flake init -t github:juspay/services-flake
+nix run
+```
+
+## Existing project
+
+services-flake uses [process-compose-flake](https://community.flake.parts/process-compose-flake) to manage the services. Let's first import the `flake-parts` modules provided by `process-compose-flake` and `services-flake` in your flake:
+```nix
+{
+  inputs.process-compose-flake.url = "github:Platonic-Systems/process-compose-flake";
+  inputs.services-flake.url = "github:juspay/services-flake";
+  ...
+  outputs = inputs:
+    inputs.flake-parts.lib.mkFlake { inherit inputs; } {
+      imports = [
+        inputs.process-compose-flake.flakeModule
+      ];
+      perSystem = { ... }: {
+        process-compose."default" = {
+          imports = [
+            inputs.services-flake.processComposeModules.default
+          ];
+        };
+      }
+    };
+}
+```
+As an example, let's add the [[redis]] service to your flake:
+```nix
+# Inside `perSystem.process-compose.default`
+{
+  services.redis."r1".enable = true;
+}
+```
+
+Time to run the service:
+```sh
+nix run
+```
+
+## Under the hood
+
+- The `services-flake` module configures [process settings](https://community.flake.parts/process-compose-flake#usage) for a service. In simple terms, it handles stuff like health checks, restart policies, setup scripts, etc. by using the easy to configure APIs provided by `process-compose-flake`.
+- The `process-compose-flake` module uses these settings to generate `packages.${system}.default`[^how-default] (`nix run` above, runs this package by default), which runs [process-compose](https://github.com/F1bonacc1/process-compose) with the generated YAML configuration[^sample-config].
+
+[^how-default]: `default` is the name of the process group that is derived from `process-compose.<name>` in `perSystem.process-compose`.
+
+[^sample-config]: See the example configuration from the [getting started](https://f1bonacc1.github.io/process-compose/intro/) section of the process-compose docs.