Correct spelling mistakes.

code/renderergl2/tr_shader.c

@@ -2794,7 +2794,7 @@ static shader_t *GeneratePermanentShader( void ) {
 VertexLightingCollapse
 
 If vertex lighting is enabled, only render a single
-pass, trying to guess which is the correct one to best aproximate
+pass, trying to guess which is the correct one to best approximate
 what it is supposed to look like.
 =================
 */
@@ -3214,18 +3214,18 @@ be defined for every single image used in the game, three default
 shader behaviors can be auto-created for any image:
 
 If lightmapIndex == LIGHTMAP_NONE, then the image will have
-dynamic diffuse lighting applied to it, as apropriate for most
+dynamic diffuse lighting applied to it, as appropriate for most
 entity skin surfaces.
 
 If lightmapIndex == LIGHTMAP_2D, then the image will be used
 for 2D rendering unless an explicit shader is found
 
 If lightmapIndex == LIGHTMAP_BY_VERTEX, then the image will use
-the vertex rgba modulate values, as apropriate for misc_model
+the vertex rgba modulate values, as appropriate for misc_model
 pre-lit surfaces.
 
 Other lightmapIndex values will have a lightmap stage created
-and src*dest blending applied with the texture, as apropriate for
+and src*dest blending applied with the texture, as appropriate for
 most world construction surfaces.
 
 ===============