Release v0.2.0-nightly-20230327

What's Changed

• feat: flush all tables on shutdown by @waynexia in #1185
• docs: update document string and site by @waynexia in #1211
• feat(to_unixtime): add initial implementation by @etolbakov in #1186
• chore: rename params in flush api by @killme2008 in #1213
• refactor: execute insert with select in query engine by @MichaelScofield in #1181
• docs: use CDN for logos by @waynexia in #1219
• fix: range func tests by @waynexia in #1221
• fix: Holds FileHandle in ParquetReader to avoid the purger purges it by @evenyag in #1224
• feat: execute "delete" in query engine (in the form of "LogicalPlan") by @MichaelScofield in #1222
• feat: metasrv collects datanode heartbeats for region failure detection by @MichaelScofield in #1214
• feat: slicing PyVector&Create DataFrame from sql by @discord9 in #1190
• fix: allow larger compaction window to reduce parallel task num by @v0y4g3r in #1223
• fix: skip empty parquet by @v0y4g3r in #1236
• refactor: make sql function in scripts return a list of column vectors by @killme2008 in #1243

Full Changelog: v0.1.2...v0.2.0-nightly-20230327