Move CODING_STYLE to markdown

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

CODING_STYLE → CODING_STYLE.md

@@ -1,41 +1,49 @@
+
 - Indentation in tabs, 8 characters wide, spaces after the tabs where
   vertical alignment is required (see below)
 
+**Note: this file uses spaces due to markdown rendering issues for tabs.
+  Code must be implemented using tabs.**
+
 - Max line width 80ch, do not break up printed strings though
 
 - Break up long lines at logical groupings, one line for each logical group
 
-  int a = somelongname() +
-  	  someotherlongname();
+```c
+int a = somelongname() +
+        someotherlongname();
 
-  if (a < 0 &&
-      (b > 20 & d < 10) &&
-      d != 0.0)
+if (a < 0 &&
+    (b > 20 & d < 10) &&
+    d != 0.0)
 
 
-  somelongfunctioncall(arg1,
-  		       arg2,
-  		       arg3);
+somelongfunctioncall(arg1,
+                     arg2,
+                     arg3);
+```
 
 - Function declarations: return type on separate line, {} on separate line,
   arguments broken up as above.
 
-  static inline int
-  foobar(int a, int b)
-  {
+```c
+static inline int
+foobar(int a, int b)
+{
 
-  }
+}
 
-  void
-  somenamethatiswaytoolong(int a,
-  			   int b,
-  			   int c)
-  {
-  }
+void
+somenamethatiswaytoolong(int a,
+                         int b,
+                         int c)
+{
+}
+```
 
-- /* comments only */, no // comments
+- `/* comments only */`, no `// comments`
 
-- variable_name, not VariableName or variableName. same for functions.
+- `variable_name`, not `VariableName` or `variableName`. same for functions.
 
 - no typedefs of structs, enums, unions
 
@@ -48,70 +56,80 @@
   at the top.
   Exception: basic loop variables, e.g. for (int i = 0; ...)
 
-  int a;
-  int c;
+```c
+int a;
+int c;
 
-  if (foo) {
-  	int b;
+if (foo) {
+        int b;
 
-  	c = get_value();
-  	usevalue(c);
-  }
+        c = get_value();
+        usevalue(c);
+}
 
-  if (bar) {
-  	c = get_value();
-  	useit(c);
-  }
+if (bar) {
+        c = get_value();
+        useit(c);
+}
+```
 
 - do not mix function invocations and variable definitions.
 
   wrong:
 
-  {
-  	  int a = foo();
-  	  int b = 7;
-  }
+```c
+{
+        int a = foo();
+        int b = 7;
+}
+```
 
   right:
-  {
-  	  int a;
-  	  int b = 7;
+```c
+{
+        int a;
+        int b = 7;
 
-  	  a = foo();
-  }
+        a = foo();
+}
+```
 
-  There are exceptions here, e.g. tp_libinput_context(),
-  litest_current_device()
+  There are exceptions here, e.g. `tp_libinput_context()`,
+  `litest_current_device()`
 
 - if/else: { on the same line, no curly braces if both blocks are a single
   statement. If either if or else block are multiple statements, both must
   have curly braces.
 
-  if (foo) {
-  	blah();
-  	bar();
-  } else {
-  	a = 10;
-  }
+```c
+if (foo) {
+        blah();
+        bar();
+} else {
+        a = 10;
+}
+```
 
-- public functions MUST be doxygen-commented, use doxygen's @foo rather than
-  \foo notation
+- public functions MUST be doxygen-commented, use doxygen's `@foo` rather than
+  `\foo` notation
 
-- include "config.h" comes first, followed by system headers, followed by
+- `#include "config.h"` comes first, followed by system headers, followed by
   external library headers, followed by internal headers.
   sort alphabetically where it makes sense (specifically system headers)
 
-  #include "config.h"
+```c
+#include "config.h"
 
-  #include <stdio.h>
-  #include <string.h>
+#include <stdio.h>
+#include <string.h>
 
-  #include <libevdev/libevdev.h>
+#include <libevdev/libevdev.h>
 
-  #include "libinput-private.h"
+#include "libinput-private.h"
+```
 
 - goto jumps only to the end of the function, and only for good reasons
   (usually cleanup). goto never jumps backwards
 
-- Use stdbool.h's bool for booleans within the library (instead of 'int').
+- Use stdbool.h's bool for booleans within the library (instead of `int`).
   Exception: the public API uses int, not bool.