exclude docs and tests from sdist (#570)

njzjz · web-flow · commit f608def67bcc · 2023-11-03T10:59:13.000+08:00
Per https://pypi.org/project/dpdata/0.2.17/#files, these files are too large.
diff --git a/MANIFEST.in b/MANIFEST.in
@@ -0,0 +1,3 @@
+prune docs
+prune tests
+prune plugin_example
