[avgvi]

Updates the 0.14.0 changelog so each entry describes the change and names the pull request in this repository, without crediting or linking to pull requests elsewhere.

• The opening line now reads "streaming-community is a fork of MosaicML Streaming 0.13.0. Each entry names the pull request in this repository."
• The six fix entries keep their descriptions and this repository's PR numbers (Fix the get_shm_prefix follower race #20, Stop parsing Windows drive letters as cloud schemes #21, Keep nested directories in merge_index shard paths #23, Honor multi-epoch batch durations in the simulator #24, Fix non-nullable ArrayType columns and forward exist_ok in dataframe_to_mds #25, Do not evict local-only shards under cache_limit #27).
• "Replace upstream CI" reads "Replace the inherited CI".

Text only; no code changes.