Add documentation for Go configuration options

fern/products/sdks/overview/go/configuration.mdx

@@ -3,6 +3,174 @@ title: Go Configuration
 description: Configuration options for the Fern Go SDK.
 ---
 
-# Go Configuration
+You can customize the behavior of the Go SDK generator in `generators.yml`:
 
-Discover how to configure the Fern Go SDK for your project. 
+```yaml {7-8}
+default-group: local
+groups:
+  local:
+    generators:
+      - name: fernapi/fern-go-sdk
+        version: <Markdown src="/snippets/version-number.mdx"/>
+        config:
+          packageName: acme
+        output:
+          location: local-file-system
+          path: ../generated/go
+```
+
+## SDK Configuration Options
+
+<ParamField path="module" type="ModuleConfigSchema" required={false}>
+Use this option if you plan to distribute the generated Go SDK as a separate, published Go module.
+
+<Note>If you only plan to use the generated SDK within your own Go module, use the `importPath` configuration option instead.</Note>
+
+You can generate the Go SDK code into a separate module (defined with its own `go.mod`)
+with the following `generators.yml` configuration:
+
+```yaml {7-9}
+default-group: local
+groups:
+  local:
+    generators:
+      - name: fernapi/fern-go-sdk
+        version: 0.13.0
+        config:
+          module:
+            path: github.com/<YOUR_ORGANIZATION>/<YOUR_REPOSITORY>
+        output:
+          location: local-file-system
+          path: ../generated/go
+```
+
+This configuration will generate a `go.mod` alongside the rest of the Go SDK code at the target output
+location. With this, `import` statements within the generated Go SDK are all resolved from the configured
+module path.
+
+By default, the generated `go.mod` will be set to `1.13`. You can override this behavior by specifying
+the `version` key:
+
+```yaml {10}
+default-group: local
+groups:
+  local:
+    generators:
+      - name: fernapi/fern-go-sdk
+        version: 0.13.0
+        config:
+          module:
+            path: github.com/<YOUR_ORGANIZATION>/<YOUR_REPOSITORY>
+            version: "1.19"
+        output:
+          location: local-file-system
+          path: ../generated/go
+```
+
+If you want to depend on the generated Go SDK locally (without distributing it as a separate Go module),
+and you use the `module` configuration option, you will need to modify your project's top-level `go.mod` to include a [`replace`](https://go.dev/doc/modules/gomod-ref#replace) statement:
+
+```go
+module github.com/your/module
+
+require "github.com/your/sdk" v0.0.0
+replace "github.com/your/sdk" v0.0.0 => "path/to/generated/sdk"
+```
+
+</ParamField>
+
+<ParamField path="packageName" type="string" required={false}>
+</ParamField>
+
+<ParamField path="importPath" type="string" required={false}>
+Use this option if you plan to depend on the generated Go SDK from within your project, and **not** depend on it as a separate, published Go module.
+
+<Note>If you plan to to distribute the generated Go SDK as a separate, published Go module, use the `module` configuration option instead.</Note>
+
+You can generate the Go SDK code into a `gen/go/api` package with the following `generators.yml`
+configuration:
+
+```yaml {7-8}
+default-group: local
+groups:
+  local:
+    generators:
+      - name: fernapi/fern-go-sdk
+        version: 0.13.0
+        config:
+          importPath: github.com/<YOUR_ORGANIZATION>/<YOUR_REPOSITORY>/generated/go
+        output:
+          location: local-file-system
+          path: ../generated/go
+```
+<Info>You must update the `<YOUR_ORGANIZATION>` and `<YOUR_REPOSITORY>` placeholders
+with the relevant elements in your `go.mod` path. In this case, the generated Go SDK uses the same `go.mod` path used by the rest of your Go module.</Info>
+
+</ParamField>
+
+<ParamField path="alwaysSendRequiredProperties" type="boolean" required={false}>
+</ParamField>
+
+<ParamField path="clientConstructorName" type="string" required={false}>
+</ParamField>
+
+<ParamField path="clientName" type="string" required={false}>
+</ParamField>
+
+<ParamField path="enableExplicitNull" type="boolean" required={false}>
+By default, it's impossible to send an explicit JSON `null` for optional parameters. `enableExplicitNull: true` opts in to generating a generic `Optional[T]` type that can be used to distinguish between a `nil` value (nothing is sent), a non-`nil` value (the value is sent), and an explicit null (a `null` value is sent). This is particularly useful for `PATCH` endpoints.
+
+The `Optional` and `Null` constructor functions will be included at the root of your module and can be
+used like so:
+
+```go
+client := acmeclient.NewClient()
+updatedFoo, err := client.Foo.Update(
+  context.TODO(),
+  &acme.UpdateFooRequest{
+    Name: acme.Optional("example"),
+    Tag:  acme.Null[string](),
+  },
+  // Serialized as {"name":"example","tag":null}
+)
+```
+
+An example configuration:
+
+```yaml {7-8}
+default-group: local
+groups:
+  local:
+    generators:
+      - name: fernapi/fern-go-sdk
+        version: 0.13.0
+        config:
+          enableExplicitNull: true
+        output:
+          location: local-file-system
+          path: ../generated/go
+```
+
+<Note>This feature requires generics, so the generated `go.mod` will be upgraded to `1.18` (as opposed to `1.13`).</Note>
+</ParamField>
+
+<ParamField path="exportedClientName" type="string" required={false}>
+</ParamField>
+
+<ParamField path="includeLegacyClientOptions" type="boolean" required={false}>
+</ParamField>
+
+<ParamField path="inlinePathParameters" type="boolean" required={false}>
+</ParamField>
+
+<ParamField path="inlineFileProperties" type="boolean" required={false}>
+</ParamField>
+
+<ParamField path="packageLayout" type="'flat' | 'nested'" required={false}>
+</ParamField>
+
+<ParamField path="union" type="'v0' | 'v1'" required={false}>
+</ParamField>
+
+<ParamField path="useReaderForBytesRequest" type="boolean" required={false}>
+</ParamField>