docs: Set minor version chenge to first level in changelog

Author: ghusta

CHANGELOG.md

@@ -20,7 +20,7 @@ See https://www.postgresql.org/about/news/postgresql-172-166-1510-1415-1318-and-
 Upgrade to PostgreSQL 17.1.  
 See https://www.postgresql.org/about/news/postgresql-171-165-159-1414-1317-and-1221-released-2955/
 
-## 2.12.0 (2024-09-27)
+# 2.12.0 (2024-09-27)
 Upgrade to PostgreSQL 17.0.  
 See https://www.postgresql.org/about/news/postgresql-17-released-2936/
 
@@ -40,7 +40,7 @@ See https://www.postgresql.org/about/news/postgresql-162-156-1411-1314-and-1218-
 Upgrade to PostgreSQL 16.1.  
 See https://www.postgresql.org/about/news/postgresql-161-155-1410-1313-1217-and-1122-released-2749/
 
-## 2.11.0 (2023-09-16)
+# 2.11.0 (2023-09-16)
 Upgrade to PostgreSQL 16.0.  
 See https://www.postgresql.org/about/news/postgresql-16-released-2715/
 
@@ -60,18 +60,18 @@ See https://www.postgresql.org/about/news/postgresql-152-147-1310-1214-and-1119-
 Upgrade to PostgreSQL 15.1.  
 See https://www.postgresql.org/about/news/postgresql-151-146-139-1213-1118-and-1023-released-2543/
 
-## 2.10.0 (2022-11-06)
+# 2.10.0 (2022-11-06)
 - Add table _country_flag_
 
-## 2.9.0 (2022-10-28)
+# 2.9.0 (2022-10-28)
 - Add some samples in _city.local_name_ 
 - Fix some data in _city_ for cities in France
 
-## 2.8.0 (2022-10-26)
+# 2.8.0 (2022-10-26)
 - Use CSV for external data files
 - Add _city.local_name_ column
 
-## 2.7.0 (2022-10-18)
+# 2.7.0 (2022-10-18)
 Upgrade to PostgreSQL 15.0.  
 See https://www.postgresql.org/about/news/postgresql-15-released-2526/
 
@@ -87,41 +87,41 @@ See https://www.postgresql.org/about/news/postgresql-144-released-2470/
 Upgrade to PostgreSQL 14.3.  
 See https://www.postgresql.org/about/news/postgresql-143-137-1211-1116-and-1021-released-2449/
 
-## 2.6 (2021-10-01)
+# 2.6 (2021-10-01)
 Upgrade to PostgreSQL 14.  
 See https://www.postgresql.org/about/news/postgresql-14-released-2318/
 
-## 2.5 (2020-09-25)
+# 2.5 (2020-09-25)
 Upgrade to PostgreSQL 13.  
 See https://www.postgresql.org/about/news/2077/
 
-## 2.4 (2019-10-03)
+# 2.4 (2019-10-03)
 Upgrade to PostgreSQL 12.  
 See https://www.postgresql.org/about/news/1976/
 
-## 2.3 (2018-10-19)
+# 2.3 (2018-10-19)
 Upgrade to PostgreSQL 11.  
 See https://www.postgresql.org/about/news/1894/
 
 ## 2.2.1 (2018-08-13)
 Add HEALTHCHECK in Dockerfile (#2).
 
-## 2.2 (2017-10-06)
+# 2.2 (2017-10-06)
 Upgrade to PostgreSQL 10.  
 See https://www.postgresql.org/about/news/1786/ 
 
 ## 2.1.1 (2017-10-05)
 Simplify Dockerfile (no need for zipped SQL scripts)
 
-## 2.1 (2016-06-22)
+# 2.1 (2016-06-22)
 Add _country_fk_ (city.country_code -> country.code)
 
-## 2.0 (2016-05-17)
+# 2.0 (2016-05-17)
 Upgrade to PostgreSQL 9.6.  
 Normalization : change table and columns names to [snake case](https://en.wikipedia.org/wiki/Snake_case).  
 See also this question on SO : [PostgreSQL naming conventions](http://stackoverflow.com/questions/2878248/postgresql-naming-conventions). 
 
-## 1.0 (2016-05-16)
+# 1.0 (2016-05-16)
 Initial release.  
 Based on PostgreSQL 9.5.  
 Source : [world-1.0](http://pgfoundry.org/frs/shownotes.php?release_id=366) database (2005-12-02).