Update C_syntax.md

Added index of topics and changed layout for variables

Author: arteknix

LearningC/C_Language_Shorts/C_syntax.md

@@ -3,24 +3,47 @@
 C is a language with static strong typing,
 This means that you cannot change a variable's type or size once you've declared it.\
 You can only use variables you previously declared (or included from other files)
+### Index
+
+> [Data Types](#variable-types) 
+>   >  numbers \
+>   >  arrays \
+>   >  struct 
+> 
+> [Functions](#functions) \
+> [Conditional Statements](#conditional) 
+>  > if / then / else \
+>  > switch / case
+>  
+> [Loop Statements](#loop)
+>  > while / do \
+>  > for
+>  
 
 ## Variable Types
 
 ### Numbers:
-- bool `#include <stdbool.h>`
-  - true or false
-- char (signed/unsigned)
-  - 8-bit = 1 byte
-- short (signed/unsigned)
-  - 2-byte 
-- integer (signed/unsigned)
-  - 4 8 16 byte depending on os/cpu
-- long (signed/unsigned)
-  - longer integer. if you need more you can use _long long_
-- float
-  - real number 
-- double
-  - double precision real number
+> **bool** `#include <stdbool.h>`:
+>   > true or false 
+> 
+> **char** (signed/unsigned):
+>   > 8-bit = 1 byte 
+> 
+> **short** (signed/unsigned):
+>   > 2-byte 
+> 
+> **integer** (signed/unsigned):
+>   > 4 8 16 byte depending on os/cpu 
+> 
+> **long** (signed/unsigned):
+>   > longer integer. if you need more you can use _long long_
+> 
+> **float**:
+>   > real number (8-bit?)
+> 
+> **double**:
+>   > double precision real number (16-bit?)
+>   
 
 >  [!NOTE]
 >  For **intergers** we specify the size explicitly when it matters: