Update CONTRIBUTING.md

CONTRIBUTING.md

@@ -1,11 +1,45 @@
 # Coding standards
 
+## Literal structure
+
 * 4 spaces are used for tabulation. No tabs are allowed.
 * Unix line endings are used.
-* Curlies are always explicitly written.
+* Curlies are always explicitly written, even for single statements.
 * No trailing whitespaces at the end of lines.
 * Insert closing newline at the end of files.
 
+## Naming identifiers
+
+Functions are written with UpperCamelCase and noun follows verb.
+
+```
+DoThis();
+```
+
+Whenever a file exposes a group of functions as a consistent API the functions should be prefixed with the group name, followed by `_`, followed by the individual function names.
+
+```
+void LedDriver_WriteBuffer(uint8_t i2cAddress, uint8_t buffer[], uint8_t size);
+void LedDriver_WriteRegister(uint8_t i2cAddress, uint8_t reg, uint8_t val);
+void LedDriver_SetAllLedsTo(uint8_t val);
+```
+
+Variables and function parameters are written with lowerCamelCase.
+
+```
+uint8_t myVariable;
+```
+
+Type names are written with underscores, and end with `_t`. Type members are written with lowerCamelCase.
+
+```
+typedef struct {
+    uint8_t acceleration;
+    uint8_t maxSpeed;
+    uint8_t roles[LAYER_COUNT];
+} pointer_t;
+```
+
 ## If
 
 ```
@@ -32,7 +66,7 @@ while (condition) {
 }
 ```
 
-## function
+## function declaration
 
 ```
 void do_this()