WIP docs: commenting in player.c/player.h and README updates

src/player.c

@@ -5,11 +5,15 @@
 
 #include "raylib.h"
 
+// let's a go!
+
 void UpdatePlayerControls(void)
 {
+    // if there isn't a player, you probably can't do much
     if (!player)
         return;
 
+    // if a key pressed, push player to the left
     if (IsKeyDown(KEY_A))
     {
         ApplyForce(
@@ -17,7 +21,7 @@ void UpdatePlayerControls(void)
             (Vector2){-PLAYER_FORCE, 0}
         );
     }
-
+    // if d key pressed, push player to the right
     if (IsKeyDown(KEY_D))
     {
         ApplyForce(
@@ -25,7 +29,7 @@ void UpdatePlayerControls(void)
             (Vector2){PLAYER_FORCE, 0}
         );
     }
-
+    // if sspace key pressed (and player isn't already jumping), push player upward
     if (IsGrounded(player) &&
         IsKeyPressed(KEY_SPACE))
     {