added README and gitignore

.gitignore

@@ -0,0 +1 @@
+target

README.md

@@ -0,0 +1,10 @@
+# Project
+
+This is a classic A* implementation written in c.
+The project is split into:
+- `frontend`: An interactive raylib visualization
+- `backend`: The independent algorithm (can be used elsewhere) 
+
+## Background
+
+I wrote this as a prototype and copied it almost 1 to 1 into my [other projects](https://git.magnusku.de/Magnus/topdown_game) code.

src/astar.c

@@ -5,10 +5,19 @@
 
 #include "../include/astar.h"
 
+bool is_collider(int i) {
+	if (i == -1 || i == 10) {
+		return false;
+	}
+	else {
+		return true;
+	}
+}
+
 void reset_field(afield_t *field, int** map) {
 	for (int r = 0; r < field->rows; r++) {
 		for (int c = 0; c < field->columns; c++) {
-			bool is_obstacle = map[r][c] != -1 ? true : false;
+			bool is_obstacle = is_collider(map[r][c]);
 
 			field->map[r][c] = (anode_t){
 				.parent = {-1, -1},