Modify Hello world tutorial to be shorter and easier

docs/docs/02-guide/03-hello/00-hello-world.md

@@ -0,0 +1,85 @@
+---
+description: Build your first blockchain and your first Cosmos SDK module.
+title: Hello World
+---
+
+# "Hello world!" Blockchain Tutorial with Ignite CLI
+
+**Introduction**
+
+In this tutorial, you'll build a simple blockchain using Ignite CLI that responds to a custom query with "Hello %s!", where %s is a name provided in the query. 
+This will enhance your understanding of creating custom queries in a Cosmos SDK blockchain.
+
+## Setup and Scaffold
+
+1. **Create a New Blockchain:**
+
+```bash
+ignite scaffold chain hello
+```
+
+2. **Navigate to the Blockchain Directory:**
+
+```bash
+cd hello
+```
+
+## Adding a Custom Query
+
+- **Scaffold the Query:**
+
+```bash
+ignite scaffold query say-hello name --response name
+```
+
+This command generates code for a new query, `say-hello`, which accepts a name, an input and returns it in the response.
+
+- **Understanding the Scaffolded Code:**
+
+	- `proto/hello/hello/query.proto`: Defines the request and response structure.
+	- `x/hello/client/cli/query_say_hello.go`: Contains the CLI commands for the query.
+	- `x/hello/keeper/query_say_hello.go`: Houses the logic for the query response.
+
+
+## Customizing the Query Response
+
+- **Modify `query_say_hello.go`:
+Update the `SayHello` function in `x/hello/keeper/query_say_hello.go` to return a personalized greeting.
+
+```go title="x/hello/keeper/query_say_hello.go"
+func (k Keeper) SayHello(goCtx context.Context, req *types.QuerySayHelloRequest) (*types.QuerySayHelloResponse, error) {
+	if req == nil {
+		return nil, status.Error(codes.InvalidArgument, "invalid request")
+	}
+
+	// Validation and Context unwrapping
+	ctx := sdk.UnwrapSDKContext(goCtx)
+
+	_ = ctx
+	// Custom Response
+	// highlight-next-line
+	return &types.QuerySayHelloResponse{Name: fmt.Sprintf("Hello %s!", req.Name)}, nil
+}
+```
+
+## Running the Blockchain
+
+1. **Start the Blockchain:**
+
+```bash
+ignite chain serve
+```
+
+2. **Test the Query:**
+
+Use the command-line interface to submit a query.
+
+```
+hellod q hello say-hello world
+```
+
+Expect a response: `Hello world!`
+
+## Conclusion
+
+Congratulations! 🎉 You've successfully created a blockchain module with a custom query using Ignite CLI. Through this tutorial, you've learned how to scaffold a chain, add a custom query, and modify the logic for personalized responses. This experience illustrates the power of Ignite CLI in streamlining blockchain development and the importance of understanding the underlying code for customization.