New module for parser functions

Same principle as main->lib (previous commit).

parser.h

@@ -0,0 +1,32 @@
+#ifndef PARSER_H
+#define PARSER_H
+
+#include "./lib.h"
+
+typedef struct AST
+{
+  size_t col, row;
+  enum
+  {
+    NEXT = 0,
+    PREV,
+    INC,
+    DEC,
+    OUT,
+    READ,
+    LIN,
+    LOUT
+  } type;
+  int loop_ref;
+} node_t;
+
+struct PResult
+{
+  node_t *nodes;
+  size_t size;
+};
+
+char *ast_to_str(node_t *ast, size_t size);
+struct PResult parse_buffer(buffer_t *buffer);
+
+#endif