Change rust toolchain to stable (#649)

Co-authored-by: Dmitry Novikov <novikov.dm.al@gmail.com>

docs/examples/prerequisites.mdx

@@ -19,7 +19,7 @@ All program examples and JS applications have been tested on a stable environmen
 
 You may configure a local development environment according to the information provided below or use a pre-configured Docker image as described in the [Using Docker](#using-docker) section.
 
-Current stable release: `v1.1.1`
+Current stable release: `v1.2.1`
 
 <table>
 <tr>
@@ -56,8 +56,7 @@ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
 ```
 Add Wasm target to your toolchain:
 ```bash
-rustup toolchain add nightly
-rustup target add wasm32-unknown-unknown --toolchain nightly
+rustup target add wasm32-unknown-unknown
 ```
 </td>
 </tr>
@@ -125,6 +124,8 @@ It is highly recommended to use Linux or macOS for compiling Gear node and progr
 
 | Gear node version | Runtime version | Gear libraries version | Rust toolchain version |
 | ----------------- | --------------- | ---------------------- | ---------------------- |
+| v1.2.1            | 1210            | tag = "v1.2.1"         | stable                 |
+| v1.1.1            | 1110            | tag = "v1.1.1"         | stable                 |
 | v1.0.5            | 1050            | tag = "v1.0.5"         | nightly-2023-09-18     |
 | v1.0.2            | 1020            | tag = "v1.0.2"         | nightly-2023-10-14     |
 | v1.0.1            | 1010            | tag = "v1.0.1"         | nightly-2023-10-14     |

docs/getting-started-in-5-minutes.md

@@ -33,19 +33,13 @@ This guide provides a general overview of running programs on the networks power
     curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
     ```
 
-3. Install a `nightly` version of the toolchain with `rustup`, since Gear uses the most up-to-date features `rustup` provides. `nightly-2023-09-18` is the latest version compatible with Gear.
+3. A Wasm compiler is necessary for compiling a Rust program to Wasm, add it to the toolchain.
 
     ```bash
-    rustup toolchain add nightly-2023-09-18
+    rustup target add wasm32-unknown-unknown
     ```
 
-4. Aa Wasm compiler is necessary for compiling a Rust program to Wasm, add it to the toolchain.
-
-    ```bash
-    rustup target add wasm32-unknown-unknown --toolchain nightly-2023-09-18
-    ```
-
-5. Install the `wasm-proc` utility that optimizes compiled Wasm to be more compact.
+4. Install the `wasm-proc` utility that optimizes compiled Wasm to be more compact.
 
     ```bash
     cargo install --locked --git https://github.com/gear-tech/gear.git wasm-proc
@@ -141,7 +135,7 @@ This guide provides a general overview of running programs on the networks power
 
     ```bash
     RUSTFLAGS="-C link-args=--import-memory -C linker-plugin-lto" \
-        cargo +nightly-2023-09-18 build --release --target=wasm32-unknown-unknown
+        cargo build --release --target=wasm32-unknown-unknown
     ```
 
     This command is quite verbose, so you can create cargo config and Rust toolchain override files to make it shorter. Create a `.cargo/config.toml` file in the `counter` directory with the following contents:
@@ -159,7 +153,7 @@ This guide provides a general overview of running programs on the networks power
 
     ```toml
     [toolchain]
-    channel = "nightly-2023-09-18"
+    channel = "stable"
     targets = ["wasm32-unknown-unknown"]
     profile = "default"
     ```

docs/node/setting-up.mdx

@@ -34,18 +34,18 @@ Depending on your OS you need to download the last release build of Gear node fr
 Terminal:
 
 ```bash
-curl https://get.gear.rs/gear-v1.1.1-x86_64-unknown-linux-gnu.tar.xz | tar xJ
+curl https://get.gear.rs/gear-v1.2.1-x86_64-unknown-linux-gnu.tar.xz | tar xJ
 ```
 
 or
 
-**Linux x86-64**: [gear-v1.1.1-x86_64-unknown-linux-gnu.tar.xz](https://get.gear.rs/gear-v1.1.1-x86_64-unknown-linux-gnu.tar.xz)
+**Linux x86-64**: [gear-v1.2.1-x86_64-unknown-linux-gnu.tar.xz](https://get.gear.rs/gear-v1.2.1-x86_64-unknown-linux-gnu.tar.xz)
 
 Run the node:
 
 ```
 ❯ ./gear --version
-gear 1.1.1-33ee05d5aab
+gear 1.2.1-a218853
 ```
 
 </TabItem>
@@ -55,18 +55,18 @@ gear 1.1.1-33ee05d5aab
 Terminal:
 
 ```bash
-curl https://get.gear.rs/gear-v1.1.1-aarch64-apple-darwin.tar.xz | tar xJ
+curl https://get.gear.rs/gear-v1.2.1-aarch64-apple-darwin.tar.xz | tar xJ
 ```
 
 or
 
-**macOS ARM**: [gear-v1.1.1-aarch64-apple-darwin.tar.xz](https://get.gear.rs/gear-v1.1.1-aarch64-apple-darwin.tar.xz)
+**macOS ARM**: [gear-v1.2.1-aarch64-apple-darwin.tar.xz](https://get.gear.rs/gear-v1.2.1-aarch64-apple-darwin.tar.xz)
 
 You can try to run the node:
 
 ```
 ❯ ./gear --version
-gear 1.1.1-33ee05d5aab
+gear 1.2.1-a218853
 ```
 
 </TabItem>
@@ -75,18 +75,18 @@ gear 1.1.1-33ee05d5aab
 Terminal:
 
 ```bash
-curl https://get.gear.rs/gear-v1.1.1-x86_64-apple-darwin.tar.xz | tar xJ
+curl https://get.gear.rs/gear-v1.2.1-x86_64-apple-darwin.tar.xz | tar xJ
 ```
 
 or
 
-**macOS x86-64**: [gear-v1.1.1-x86_64-apple-darwin.tar.xz](https://get.gear.rs/gear-v1.1.1-x86_64-apple-darwin.tar.xz)
+**macOS x86-64**: [gear-v1.2.1-x86_64-apple-darwin.tar.xz](https://get.gear.rs/gear-v1.2.1-x86_64-apple-darwin.tar.xz)
 
 You can try to run the node:
 
 ```
 ❯ ./gear --version
-gear 1.1.1-33ee05d5aab
+gear 1.2.1-a218853
 ```
 
 </TabItem>
@@ -96,18 +96,18 @@ gear 1.1.1-33ee05d5aab
 Terminal:
 
 ```bash
-curl -O https://get.gear.rs/gear-v1.1.1-x86_64-pc-windows-msvc.zip
+curl -O https://get.gear.rs/gear-v1.2.1-x86_64-pc-windows-msvc.zip
 ```
 
 or
 
-**Windows x86-64**: [gear-v1.1.1-x86_64-pc-windows-msvc.zip](https://get.gear.rs/gear-v1.1.1-x86_64-pc-windows-msvc.zip)
+**Windows x86-64**: [gear-v1.2.1-x86_64-pc-windows-msvc.zip](https://get.gear.rs/gear-v1.2.1-x86_64-pc-windows-msvc.zip)
 
 Unzip the downloaded package then you can try to run the node:
 
 ```
 ❯ gear.exe --version
-gear.exe 1.1.1-d02d306f97c
+gear.exe 1.2.1-a218853
 ```
 
 </TabItem>
@@ -171,7 +171,7 @@ rustup target add wasm32-unknown-unknown --toolchain nightly
 git clone https://github.com/gear-tech/gear.git
 cd gear
 # Checkout to the latest release tag
-git checkout v1.1.1 -b release-1.1.1
+git checkout v1.2.1 -b release-1.2.1
 ```
 
 :::info