Add help information to the configure script

Author: phausler

configure

@@ -135,13 +135,13 @@ def main():
     config.config_path            = config.source_root.path_by_appending(".configuration")
 
     parser = argparse.ArgumentParser(description='Configure and emit ninja build scripts for building.')
-    parser.add_argument('--target', dest='target', type=str, default=Target.default())
-    parser.add_argument('--sysroot', dest='sysroot', type=str, default=None)
-    parser.add_argument('--toolchain', dest='toolchain', type=str, default=None)
-    parser.add_argument('--linker', dest='linker', type=str, default=None)
+    parser.add_argument('--target', dest='target', type=str, default=Target.default(), help="specify the deployment target")
+    parser.add_argument('--sysroot', dest='sysroot', type=str, default=None, help="the system root directory for building")
+    parser.add_argument('--toolchain', dest='toolchain', type=str, default=None, help="the base location for finding tools to compile")
+    parser.add_argument('--linker', dest='linker', type=str, default=None, help="which linker program to use")
     parser.add_argument('--pkg-config', dest='pkg_config', type=str, default="pkg-config")
-    parser.add_argument('--bootstrap', dest='bootstrap', type=str, default=os.path.join(os.path.dirname(os.path.abspath(__file__)), "bootstrap"))
-    parser.add_argument('--reconfigure', dest='reconfigure', action="store_true")
+    parser.add_argument('--bootstrap', dest='bootstrap', type=str, default=os.path.join(os.path.dirname(os.path.abspath(__file__)), "bootstrap"), help="a directory for bootstrapping commonly used headers and libraries not associated directly with the target operating system")
+    parser.add_argument('--reconfigure', dest='reconfigure', action="store_true", help="re-generate the build script given the previous configuration")
     parser.add_argument('-v', '--verbose', dest='verbose', action="store_true")
     args, extras = parser.parse_known_args()