fix markdownlint warnings

readme.md

@@ -1,8 +1,11 @@
+<!-- markdownlint-disable MD033 -->
 <h1 align="center">deva's nixos flake</h1>
 
 <p align="center">
+   <!-- markdownlint-disable MD013 -->
    <a href="https://nixos.org"><img src="https://builtwithnix.org/badge.svg" alt="built with nix" height="20"/></a>
    <img src="https://img.shields.io/github/license/devawaves/nixos" alt="License Badge"/>
+   <!-- markdownlint-enable MD013 -->
 </p>
 
 <br>
@@ -16,8 +19,9 @@ nix flake show github:devawaves/nixos
 ```
 
 to get the disko.nix file, run:
+
 ```sh
 nix run github:devawaves/nixos#disko
 ```
 
-*more utilities can be found in [usage.md](./usage.md)*
+_more utilities can be found in [usage.md](./usage.md)_

usage.md

@@ -1,12 +1,19 @@
+# Usage
+
 Building NixOS config manually:
+
 ```sh
 sudo nixos-rebuild --flake .#hostname switch
 ```
+
 Upgrading the system implies updating the inputs one at a time:
+
 ```sh
 sudo nix flake lock --update-input <input>
 ```
+
 or all of them together:
+
 ```sh
 nix flake update --commit-lock-file
 ```