✨ Updating section 01

Author: dumindu

source/docs/a2.installation.md

@@ -4,11 +4,22 @@ title: Installation
 ## Rustup
 There are many ways to install Rust on your system. For the moment the official way to install Rust is using [Rustup](https://rustup.rs/).
 
-[📖](https://github.com/rust-lang/rustup#rustup-the-rust-toolchain-installer) Rustup installs The Rust Programming Language from the official release channels, enabling you to easily switch between **stable, beta, and nightly** compilers and keep them updated. It makes **cross-compiling** simpler with binary builds of the standard library for common platforms.
-
-[📖](https://github.com/rust-lang/rustup#installation) Rustup installs **`rustc`, `cargo`, `rustup`** and other standard tools to Cargo's `bin` directory. On Unix it is located at `$HOME/.cargo/bin` and on Windows at `%USERPROFILE%\.cargo\bin`. This is the same directory that `cargo install` will install Rust programs and Cargo plugins.
-
-💡 More information can be found on the [Github repository of Rustup project](https://github.com/rust-lang/rustup#rustup-the-rust-toolchain-installer).
+[📖](https://rust-lang.github.io/rustup/index.html) Rustup installs The Rust Programming Language from the official release channels, enabling you to easily switch between **stable, beta, and nightly** compilers and keep them updated. It makes **cross-compiling** simpler with binary builds of the standard library for common platforms.
+
+[📖](https://rust-lang.github.io/rustup/installation/index.html) Rustup installs **`rustc`, `cargo`, `rustup`** and other standard tools to Cargo's `bin` directory. On Unix it is located at `$HOME/.cargo/bin` and on Windows at `%USERPROFILE%\.cargo\bin`. This is the same directory that `cargo install` will install Rust programs and Cargo plugins.
+
+> 🔎 The main tools Rustup installs to the Cargo's `bin` directory,
+> - `rustc`: The Rust compiler.
+> - `cargo`: The Rust’s built-in package manager and the build system.
+> - `rustup`: The Rust toolchain installer.
+> - `rustfmt`: The Rust’s official tool of formatting Rust code according to style guidelines.
+> - `cargo-fmt`: Helps to run `rustfmt` on whole Rust projects, including multi-crate workspaces.
+> - `cargo-clippy`: A lint tool that provides extra checks for common mistakes and stylistic choices.
+> - `cargo-miri`:An experimental Rust interpreter, which can be used for checking for undefined-behavior.
+> - `rls`: A language server that provides support for editors and IDEs.
+> - `rustdoc`: A local copy of the Rust documentation.
+
+## Installation
 
 ### For Mac and Linux Users
 ```bash

source/docs/a3.hello_world.md

@@ -31,10 +31,13 @@ fn main() {
 fn main() {
     println!("{}, {}!", "Hello", "world"); // Hello, world!
     println!("{0}, {1}!", "Hello", "world"); // Hello, world!
-    println!("{greeting}, {name}!", greeting="Hello", name="world"); // Hello, world!
+    println!("{greeting}, {name}!", greeting = "Hello", name = "world"); // Hello, world!
 
-    println!("{:?}", [1,2,3]); // [1, 2, 3]
-    println!("{:#?}", [1,2,3]);
+    let (greeting, name) = ("Hello", "world"); // 💡 Two Variable bindings declare & initialize in one line.
+    println!("{greeting}, {name}!"); // Hello, world!
+
+    println!("{:?}", [1, 2, 3]); // [1, 2, 3]
+    println!("{:#?}", [1, 2, 3]);
     /*
         [
             1,