Fix typos [skip ci]

Found via codespell v1.18.0.dev0  
```
codespell -q 3 -L aci,ake,aline,alle,alledges,alocation,als,ang,anid,ba,beginn,behaviour,bloaded,byteorder,calculater,cancelled,cancelling,cas,cascade,centimetre,childs,colour,colours,commen,connexion,currenty,dof,doubleclick,dum,eiter,elemente,ende,feld,finde,findf,freez,hist,iff,indicies,initialisation,initialise,initialised,initialises,initialisiert,ist,kilometre,lod,mantatory,methode,metres,millimetre,modell,nd,noe,normale,normaly,nto,numer,oder,orgin,orginx,orginy,ot,pard,pres,programm,que,recurrance,rougly,seperator,serie,sinc,strack,substraction,te,thist,thru,tread,uint,unter,vertexes,wallthickness,whitespaces -S ./.git,*.po,*.ts,./ChangeLog.txt,./src/3rdParty,./src/Mod/Assembly/App/opendcm,./src/CXX,./src/zipios++,./src/Base/swig*,./src/Mod/Robot/App/kdl_cp,./src/Mod/Import/App/SCL,./src/WindowsInstaller,./src/Doc/FreeCAD.uml
```

src/Mod/Path/PathScripts/PathSurfaceSupport.py

@@ -57,7 +57,7 @@ class PathGeometryGenerator:
     PathGeometryGenerator(obj, shape, pattern)
     `obj` is the operation object, `shape` is the horizontal planar shape object,
     and `pattern` is the name of the geometric pattern to apply.
-    Frist, call the getCenterOfPattern() method for the CenterOfMass for patterns allowing a custom center.
+    First, call the getCenterOfPattern() method for the CenterOfMass for patterns allowing a custom center.
     Next, call the generatePathGeometry() method to request the path geometry shape.'''
 
     # Register valid patterns here by name