Add GPLv3 boltsparts lib (https://github.com/boltsparts/boltsparts)

LICENSE.md

@@ -46,6 +46,7 @@ The WASM build was made possible by https://github.com/DSchroer/openscad-wasm.
   + [Stemfie_OpenSCAD](#stemfie-openscad)
   + [UB.scad](#ubscad)
   + [pathbuilder](#pathbuilder)
+  + [boltsparts](#boltsparts)
   + [openscad_attachable_text3d](#openscad_attachable_text3d)
 
 ## Manifold
@@ -746,6 +747,12 @@ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 ```
 
+## boltsparts
+
+https://github.com/boltsparts/boltsparts
+
+Licensed under the [GPLv3](#gplv3).
+
 ## pathbuilder
 
 https://github.com/dinther/pathbuilder