docs: add quick-start draft

Author: jk-gan

docs/quick-start.md

@@ -0,0 +1,48 @@
+---
+id: quick-start
+title: Quick Start 
+sidebar_label: Quick Start 
+---
+
+## Quick install guide
+if you haven't installed [Rust](https://www.rust-lang.org/) yet, here is a quick guide which using rustup:
+```bash
+curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
+```
+After Rust is installed, you can use cargo to generate a new project:
+```bash
+cargo new my-app
+```
+Go to `Cargo.toml` file, add this line:
+```toml {10}
+[package]
+name = "my-app"
+version = "0.1.0"
+authors = ["Gan Jun Kai <kuhn96@gmail.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+obsidian = "0.1.0-alpha.1"
+```
+Go to `main.rs`, add these:
+```rust {1,4-11}
+use obsidian::App;
+
+fn main() {
+  let mut app = App::new();
+  let addr = ([127, 0, 0, 1], 3000).into();
+
+  app.get("/", |_ctx| "Hello World");
+
+  app.listen(&addr, || {
+    println!("server is listening to {}", &addr);
+  });
+}
+```
+
+Go to terminal type this to start your server:
+```bash
+cargo run
+```

docusaurus.config.js

@@ -29,6 +29,10 @@ module.exports = {
         {
           title: 'Docs',
           items: [
+            {
+              label: 'Quick Start',
+              to: 'docs/quick-start',
+            },
             {
               label: 'Style Guide',
               to: 'docs/doc1',

sidebars.js

@@ -7,6 +7,7 @@
 
 module.exports = {
   someSidebar: {
+    Introduction: ['quick-start'],
     Docusaurus: ['doc1', 'doc2', 'doc3'],
     Features: ['mdx'],
   },