Add description and images for ST_EnvelopesIntersect
Add description and image for ST_LocateAlong
Update description and add images for ST_LocateAlong
Add image for ST_LocateAlong
Update description ST_LocateAlong
Update images fot ST_LocateAlong
Add description and comparison for ST_PointOnSurface
Update comparison example for ST_Centroid
Update images with square root for ST_LocateAlong
Update comparison between ST_Centroid and ST_PointOnSurface
Update comparison example in include for ST_Buffer and ST_MakeEllipse
Add description and images for ST_Buffer
Update ST_Buffer with the new parameter

Conflicts:

	docs/dev/ST_Buffer.md
Merge remote-tracking branch 'upstream/gh-pages' into buffer_with_parameter
Add images for ST_PointOnSurface
Add description for ST_Relate
Add images for ST_Relate
Update description for ST_Accum and link for ST_Zmin
Merge remote-tracking branch 'upstream/gh-pages' into st_makellipse_buffer
Update description and images for ST_Buffer