Simplify coding style (#1280)

doc/coding-convention.md

@@ -1,41 +1,29 @@
-# Coding convention
+# Coding style
 
-## Language
+## Use these tools to find and fix issues.
 
-The language of this project is **C++**, and all new code must be written in C++. (Modern) C++ provides a lot of useful tools and functionalities that are beneficial for embedded software development like `constexpr`, `template` and anything that provides zero-cost abstraction.
+- Use `clang-format` to format the code.
+- Use `clang-tidy` to check the code for other potential issues.
 
-C code is accepted if it comes from another library like FreeRTOS, NimBLE, LVGL or the NRF-SDK.
-
-## Coding style
-
-The most important rule to follow is to try to keep the code as easy to read and maintain as possible.
-
-Using an autoformatter is highly recommended, but make sure it's configured properly.
-
-There are preconfigured autoformatter rules for:
-
-  * CLion (IntelliJ) in [.idea/codeStyles/Project.xml](/.idea/codeStyles/Project.xml)
-  * `clang-format`
-
-Also use `clang-tidy` to check the code for other issues.
-
-If there are no preconfigured rules for your IDE, you can use one of the existing ones to configure your IDE.
+## Follow these guidelines while writing code.
 
 - **Indentation** : 2 spaces, no tabulation
 - **Opening brace** at the end of the line
 - **Naming** : Choose self-describing variable name
   - **class** : PascalCase
   - **namespace** : PascalCase
-    - **variable** : camelCase, **no** prefix/suffix ('_', 'm_',...) for class members
+  - **variable** : camelCase, **no** prefix/suffix (`_`, `m_`,...) for class members
 - **Include guard** : `#pragma once` (no `#ifdef __MODULE__ / #define __MODULE__ / #endif`)
 - **Includes** :
   - files from the project : `#include "relative/path/to/the/file.h"`
   - external files and std : `#include <file.h>`
   - use includes relative to included directories like `src`, not relative to the current file. Don't do: `#include "../file.h"`
 - Only use [primary spellings for operators and tokens](https://en.cppreference.com/w/cpp/language/operator_alternative)
- - Use auto sparingly. Don't use auto for [fundamental/built-in types](https://en.cppreference.com/w/cpp/language/types) and [fixed width integer types](https://en.cppreference.com/w/cpp/types/integer), except when initializing with a cast to avoid duplicating the type name.
- - Examples:
-   - `auto* app = static_cast<DisplayApp*>(instance);`
-   - `auto number = static_cast<uint8_t>(variable);`
-   - `uint8_t returnValue = MyFunction();`
- - Use nullptr instead of NULL
+- Use `auto` sparingly. Don't use `auto` for [fundamental/built-in types](https://en.cppreference.com/w/cpp/language/types) and [fixed width integer types](https://en.cppreference.com/w/cpp/types/integer), except when initializing with a cast to avoid duplicating the type name.
+  ```c++
+  // Examples:
+  auto* app = static_cast<DisplayApp*>(instance);
+  auto number = static_cast<uint8_t>(variable);
+  uint8_t returnValue = MyFunction();
+  ```
+- Use `nullptr` instead of `NULL`