Add some missing info to the project file.

This was based on a review of PR #52 from @lucc, reviewed by @dbarnett, that
I didn't end up using as I set up the v1.0 build.  With this change, I've
pulled in the things in @lucc's PR that weren't there already.

Author: da4089

pyproject.toml

@@ -1,13 +1,9 @@
-[build-system]
-requires = ["flit_core >= 3.4"]
-build-backend = "flit_core.buildapi"
-
 [project]
 name = "vobject"
 description = "Python Calendar and Address object management"
 readme = "README.md"
 license = {file = "LICENSE-2.0.txt"}
-keywords = []
+keywords = ["vobject", "icalendar", "vcard", "ics", "vcf", "hcalendar"]
 
 dynamic = ["version"]
 dependencies = [
@@ -17,10 +13,11 @@ dependencies = [
 ]
 requires-python = ">= 3.8"
 authors = [
+     {name = "Jeffrey Harris", email = "jeffrey@osafoundation.org"},
 ]
 
 maintainers = [
-    {name = "David Arnold", email = "davida@pobox.com"}
+    {name = "David Arnold", email = "davida@pobox.com"},
 ]
 
 classifiers = [
@@ -42,7 +39,8 @@ classifiers = [
 ]
 
 [project.urls]
-homepage = "http://py-vobject.github.io/"
+homepage = "https://py-vobject.github.io/"
+repository = "https;//github.com/py-vobject/vobject"
 source = "https://github.com/py-vobject/vobject"
 download = "https://github.com/py-vobject/vobject/releases"
 issues = "https://github.com/py-vobject/vobject/issues"
@@ -62,6 +60,10 @@ dev = [
     "sphinx",
 ]
 
+[build-system]
+requires = ["flit_core >= 3.4"]
+build-backend = "flit_core.buildapi"
+
 [tool.flit.module]
 name = "vobject"