RSDK-11702: added a developer guide for getting started

cli/module_generate/_templates/go/DEVELOPER_GUIDE.md

@@ -0,0 +1,95 @@
+# Getting Started with Go Module Development
+
+This guide explains how to work with the files generated by `viam module generate` for Go modules.
+
+---
+### Module Setup
+
+After generating your module, always make sure your Go dependencies are up to date:
+
+run:
+```bash
+go mod tidy
+```
+---
+## Working with `module.go` and module lifecycle
+
+The generated `module.go` file contains the scaffolding for your resource. You will edit this file to add configuration, initialization, and method implementations.
+
+1. **`Validate(path string)`**
+   - Called first, before the module is created.
+   - It checks that the **Config struct** (`cfg`) for this specific resource is valid.  
+   - You can use it to ensure required fields exist and values are within valid ranges.  
+   - It also returns dependency information:  
+   - **First return:** required dependencies (other resources that must exist)  
+   - **Second return:** optional dependencies (resources that are nice to have but not required)  
+   - `path` is provided by the runtime and indicates **where this resource appears in the JSON config**, e.g., `"components.0"`. Use it in error messages to show which resource has a problem.
+
+Example:
+
+```go
+func (cfg *Config) Validate(path string) ([]string, []string, error) {
+    if cfg.Camera == "" {
+        return nil, nil, fmt.Errorf("%s: missing required field 'camera'", path)
+    }
+    return []string{"board:main"}, []string{"sensor:temp"}, nil
+}
+```
+
+2. **`new<ModuleName><ModelName>(...)`**
+   - Automatically called by the runtime after validation.
+   - Takes a generic `rawConf` from the robot’s JSON config.  
+   - Converts it into a typed `*Config`.
+   - Passes the config to `New<ModelName>` to create the resource instance.
+   - You usually won’t edit this function. 
+
+3. **`New<ModelName>(...)`**
+   - Your actual constructor.
+   - Receives the already-parsed `*Config`. 
+   - Sets up the logger, config, and any initial state.
+   - You can add hardware initialization or background tasks here.
+   - Returns the fully constructed resource instance.
+
+4. **Resource Methods**
+   - These are called based on what is being used in the robot.
+
+   - The generated file contains stubs for all required interface methods. Each currently calls `panic("not implemented")`.  
+
+   - Replace these with your logic. For example:
+
+```go
+func (r *myResource) DoCommand(ctx context.Context, cmd map[string]interface{}) (map[string]interface{}, error) {
+    r.logger.Infof("DoCommand called with: %+v", cmd)
+    return map[string]interface{}{"status": "ok"}, nil
+}
+```
+
+5. **`Close(ctx)`**
+   - Called when the module is being shut down.
+   - Use it to clean up background tasks, stop goroutines, and close hardware connections.
+
+
+### Logging
+
+Use the provided `logger` for all debug, info, and error messages. You can view these logs on the Viam app when you're module is running on any robot.
+
+Examples:
+
+```go
+// Informational message
+s.logger.Infof("Starting move sequence for arm %s", s.name)
+
+// Debug message
+s.logger.Debugf("Current joint positions: %+v", positions)
+
+// Error message
+s.logger.Errorf("Failed to move resource: %v", err)
+
+// Example in a method
+func (s *<ModuleName><ModelName>) EndPosition(ctx context.Context, extra map[string]interface{}) (spatialmath.Pose, error) {
+    s.logger.Infof("EndPosition called for resource %s", s.name)
+    return spatialmath.Pose{}, nil
+}
+```
+
+