newapkbuild: add documentation for -e (gpep517 flag)

Author: selfisekai

newapkbuild.1.scd

@@ -43,6 +43,11 @@ the generated APKBUILD file will not contain any build instructions.
 *-d* _DESC_
 	Specifies the description (pkgdesc=) for the new package.
 
+*-e*
+	Specifies that the package uses a Python PEP517 build
+	system. Python's gpep517, setuptools and wheel will be added
+	to the makedepends.
+
 *-f*
 	Forces *newapkbuild* to overwrite an existing APKBUILD, if one
 	already exists in the package directory.