Cartesian API
Create an API server in go. It will deal with a series of points represented as (x,y) coordinates on a simple 2-dimensional plane. Take a look at https://en.wikipedia.org/wiki/Cartesian_coordinate_system if you need a refresher on this concept.
It must have an api route at /api/points that accepts a GET request with the following parameters, and returns a JSON list of points that are within distance from x,y, using the Manhattan distance method. The points should be returned in order of increasing distance from the search origin.
xinteger (required). This represents thexcoordinate of the search origin.yinteger (required). This represents theycoordinate of the search origin.distanceinteger (required). This represents the Manhattan distance; points withindistancefromxandyare returned, points outside are filtered out.
The Manhattan distance is measured "block-wise", as the distance in blocks between any two points in the plane (e.g. 2 blocks down and 3 blocks over for a total of 5 blocks). It is defined as the sum of the horizontal and vertical distances between points on a grid. Formally, where p1 = (x1, y1) and p2 = (x2, y2), distance(p1,p2) = |x1-x2| + |y1-y2|.
On startup, the API server should read a list of points from data/points.json.