Merge #1286

1286: Timestamp changelog r=curquiza a=sandstrom

A timestamped changelog makes it easier to track progress, understand velocity, see if something has recently changed, etc.

https://keepachangelog.com/en/1.0.0/

Co-authored-by: sandstrom <mail+github@a16m.se>

CHANGELOG.md

@@ -1,14 +1,14 @@
-## v0.19.0
+## v0.19.0 - 2021-02-09
 
   - The snapshots are now created and then renamed in atomically (#1172)
   - Fix a race condition when an update and a document addition are processed immediately one after the other (#1176)
   - Latin synonyms are normalized during indexation (#1174)
 
-## v0.18.1
+## v0.18.1 - 2021-01-14
 
   - Fix unexpected CORS error (#1185)
 
-## v0.18.0
+## v0.18.0 - 2021-01-11
 
   - Integration with the new tokenizer (#1091)
   - Fix setting consistency bug (#1128)
@@ -16,7 +16,7 @@
   - Increase default payload size (#1147)
   - Improvements to code quality (#1167, #1165, #1126, #1161)
 
-## v0.17.0
+## v0.17.0 - 2020-11-30
   - Fix corrupted data during placeholder search (#1089)
   - Remove maintenance error from http (#1082)
   - Disable frontend in production (#1097)
@@ -28,12 +28,12 @@
   - Improve script `download-latest.sh` (#1054)
   - Bump dependencies version (#1056, #1057, #1059)
 
-## v0.16.0
+## v0.16.0 - 2020-11-02
 
   - Automatically create index on document push if index doesn't exist (#914)
   - Sort displayedAttributes and facetDistribution (#946)
 
-## v0.15.0
+## v0.15.0 - 2020-09-30
 
   - Update actix-web dependency to 3.0.0 (#963)
   - Consider an empty query to be a placeholder search (#916)