Add description and images for ST_BoundingCircle
Add description and image for ST_Expand
Update examples and images for ST_Expand
Add description and images for ST_Extrude
Add description for ST_MakeEnvelope
Add description, comparison and image for ST_MinimumRectangle
Update description and image for ST_MinimuRectangle and add comparison with ST_Envelope
Add description and images for ST_OctongonalEnvelope
Update the diffrente description
Update ST_OctogonalEnvelope and mini correction about other functions
Update example ST_Extrude
Update see also for ST_Expand
Update link for ST_OctogonalEnvelope
Correct ST_BoundingCircle @mlecoeuvre
Correct ST_Envelope and comparision @mlecoeuvre
Automatic format
Correct ST_Expand @mlecoeuvre
Correct ST_Extrude @mlecoeuvre
Correct ST_MakeEnvelope @mlecoeuvre
Correct ST_MinimumRectangle @mlecoeuvre