docs: fix MD031 markdown lint

[MD031/blanks-around-fences](https://github.com/DavidAnson/markdownlint/blob/v0.38.0/doc/md031.md) : Fenced code blocks should be surrounded by blank lines

Author: xtqqczze

.markdownlint.jsonc

@@ -0,0 +1,4 @@
+{
+    // MD031/blanks-around-fences : Fenced code blocks should be surrounded by blank lines
+    "MD031": true
+}

COMPILING.md

@@ -9,24 +9,30 @@ The easiest, and recommended way to get Rust is to use [rustup](https://rustup.r
 
 #### Additional Rust tools - `rustfmt`
 To ensure a consistent codebase, we utilise [`rustfmt`](https://github.com/rust-lang/rustfmt) and [`clippy`](https://github.com/rust-lang/rust-clippy), which are installed by default with `rustup` these days, else they can be installed manually with:
+
 ```bash
 rustup component add rustfmt
 rustup component add clippy
 ```
+
 Using `cargo fmt` and `cargo clippy` is not optional, as our CI checks against this repo's rules.
 
 ### General dependencies
 Along with Rust, you will also require a C compiler.
 
 On Debian/Ubuntu, install with:
+
 ```shell
 sudo apt-get install build-essential
 
 ```
+
 On Fedora systems, install with:
+
 ```shell
 sudo dnf install gcc
 ```
+
 ### Audio library dependencies
 Depending on the chosen backend, specific development libraries are required.
 
@@ -47,11 +53,14 @@ Depending on the chosen backend, specific development libraries are required.
 ###### For example, to build an ALSA based backend, you would need to run the following to install the required dependencies:
 
 On Debian/Ubuntu:
+
 ```shell
 sudo apt-get install libasound2-dev pkg-config
 
 ```
+
 On Fedora systems:
+
 ```shell
 sudo dnf install alsa-lib-devel
 ```
@@ -86,11 +95,13 @@ This is the **default choice** and provides the best compatibility. It integrate
 
 **Dependencies:**
 On Debian/Ubuntu:
+
 ```shell
 sudo apt-get install libssl-dev pkg-config
 ```
 
 On Fedora:
+
 ```shell
 sudo dnf install openssl-devel pkg-config
 ```
@@ -119,6 +130,7 @@ Uses a Rust-based TLS implementation with certificate authority (CA) verificatio
 **No additional system dependencies required** - rustls is implemented in Rust (with some assembly for performance-critical cryptographic operations) and doesn't require external libraries like OpenSSL.
 
 #### Building with specific TLS backends
+
 ```bash
 # Default (native-tls)
 cargo build

CONTRIBUTING.md

@@ -34,6 +34,7 @@ Make any changes that you are going to make to the code, but do not commit yet.
 Unless your changes are negligible, please add an entry in the "Unreleased" section of `CHANGELOG.md`. Refer to [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) for instructions on how this entry should look like. If your changes break the API such that downstream packages that depend on librespot need to update their source to still compile, you should mark your changes as `(breaking)`.
 
 Make sure that the code is correctly formatted by running:
+
 ```bash
 cargo fmt --all
 ```
@@ -45,6 +46,7 @@ cargo build
 ```
 
 Once it has built, check for common code mistakes by running:
+
 ```bash
 cargo clippy
 ```

README.md

@@ -40,16 +40,19 @@ We recently switched to using [Rodio](https://github.com/tomaka/rodio) for audio
 For Linux, you will need to run the additional commands below, depending on your distro.
 
 On Debian/Ubuntu, the following command will install these dependencies:
+
 ```shell
 sudo apt-get install build-essential libasound2-dev
 ```
 
 On Fedora systems, the following command will install these dependencies:
+
 ```shell
 sudo dnf install alsa-lib-devel make gcc
 ```
 
 librespot currently offers the following selection of [audio backends](https://github.com/librespot-org/librespot/wiki/Audio-Backends):
+
 ```
 Rodio (default)
 ALSA
@@ -62,9 +65,11 @@ SDL
 Pipe
 Subprocess
 ```
+
 Please check [COMPILING.md](COMPILING.md) for detailed information on TLS, audio, and discovery backend dependencies, or the [Compiling](https://github.com/librespot-org/librespot/wiki/Compiling#general-dependencies) entry on the wiki for additional backend specific dependencies.
 
 Once you've installed the dependencies and cloned this repository you can build *librespot* with the default features using Cargo.
+
 ```shell
 cargo build --release
 ```
@@ -80,14 +85,17 @@ librespot is also available via official package system on various operating sys
 ## Usage
 A sample program implementing a headless Spotify Connect receiver is provided.
 Once you've built *librespot*, run it using :
+
 ```shell
 target/release/librespot --name DEVICENAME
 ```
 
 The above is a minimal example. Here is a more fully fledged one:
+
 ```shell
 target/release/librespot -n "Librespot" -b 320 -c ./cache --enable-volume-normalisation --initial-volume 75 --device-type avr
 ```
+
 The above command will create a receiver named ```Librespot```, with bitrate set to 320 kbps, initial volume at 75%, with volume normalisation enabled, and the device displayed in the app as an Audio/Video Receiver. A folder named ```cache``` will be created/used in the current directory, and be used to cache audio data and credentials.
 
 A full list of runtime options is available [here](https://github.com/librespot-org/librespot/wiki/Options).