Fix Shader:send example;

api/init.lua

@@ -12645,7 +12645,7 @@ return {
               examples = {
                 {
                   description = "Updating a `vec3` uniform:",
-                  code = "function lovr.load()\n  shader = lovr.graphics.newShader [[\n    uniform vec3 offset;\n    vec4 lovrMain() {\n      vec4 vertex = lovrVertex;\n      vertex.xyz += offset;\n      return lovrProjection * lovrTransform * vertex;\n    }\n  ]]\n\n  shader:send('offset', { .3, .7, 0 })\nend"
+                  code = "function lovr.load()\n  shader = lovr.graphics.newShader([[\n    uniform vec3 offset;\n    vec4 lovrMain() {\n      vec4 vertex = lovrVertex;\n      vertex.xyz += offset;\n      return lovrProjection * lovrTransform * vertex;\n    }\n  ]], nil)\n\n  shader:send('offset', { .3, .7, 0 })\nend"
                 }
               }
             },

api/lovr/graphics/Shader/send.lua

@@ -102,14 +102,14 @@ return {
     description = 'Updating a `vec3` uniform:',
     code = [=[
       function lovr.load()
-        shader = lovr.graphics.newShader [[
+        shader = lovr.graphics.newShader([[
           uniform vec3 offset;
           vec4 lovrMain() {
             vec4 vertex = lovrVertex;
             vertex.xyz += offset;
             return lovrProjection * lovrTransform * vertex;
           }
-        ]]
+        ]], nil)
 
         shader:send('offset', { .3, .7, 0 })
       end