docs: fix changelog header to consistent size (#166)

Co-authored-by: Anthonios Partheniou <partheniou@google.com>

packages/google-area120-tables/CHANGELOG.md

@@ -1,6 +1,6 @@
 # Changelog
 
-### [0.6.1](https://github.com/googleapis/python-area120-tables/compare/v0.6.0...v0.6.1) (2022-03-05)
+## [0.6.1](https://github.com/googleapis/python-area120-tables/compare/v0.6.0...v0.6.1) (2022-03-05)
 
 
 ### Bug Fixes
@@ -25,7 +25,7 @@
 
 * add autogenerated code snippets ([ae17805](https://github.com/googleapis/python-area120-tables/commit/ae17805b6ea2307947129caba2185ade52a5e74c))
 
-### [0.5.1](https://www.github.com/googleapis/python-area120-tables/compare/v0.5.0...v0.5.1) (2021-11-01)
+## [0.5.1](https://www.github.com/googleapis/python-area120-tables/compare/v0.5.0...v0.5.1) (2021-11-01)
 
 
 ### Bug Fixes
@@ -46,21 +46,21 @@
 * add context manager support in client ([#96](https://www.github.com/googleapis/python-area120-tables/issues/96)) ([8990f1b](https://www.github.com/googleapis/python-area120-tables/commit/8990f1b4539f8bf0d3a327c4327a12d486447cbf))
 * add trove classifier for python 3.9 and python 3.10 ([#99](https://www.github.com/googleapis/python-area120-tables/issues/99)) ([c9cee0f](https://www.github.com/googleapis/python-area120-tables/commit/c9cee0f8cb1bf6ddb4b7bcedfd88494e9cedcf32))
 
-### [0.4.4](https://www.github.com/googleapis/python-area120-tables/compare/v0.4.3...v0.4.4) (2021-09-30)
+## [0.4.4](https://www.github.com/googleapis/python-area120-tables/compare/v0.4.3...v0.4.4) (2021-09-30)
 
 
 ### Bug Fixes
 
 * improper types in pagers generation ([18767c6](https://www.github.com/googleapis/python-area120-tables/commit/18767c6fe872942866266c0530a95a8d5160b8e5))
 
-### [0.4.3](https://www.github.com/googleapis/python-area120-tables/compare/v0.4.2...v0.4.3) (2021-09-24)
+## [0.4.3](https://www.github.com/googleapis/python-area120-tables/compare/v0.4.2...v0.4.3) (2021-09-24)
 
 
 ### Bug Fixes
 
 * add 'dict' annotation type to 'request' ([ee57f81](https://www.github.com/googleapis/python-area120-tables/commit/ee57f81534ac3cc21ced61659ee1796dbe5b4210))
 
-### [0.4.2](https://www.github.com/googleapis/python-area120-tables/compare/v0.4.1...v0.4.2) (2021-07-26)
+## [0.4.2](https://www.github.com/googleapis/python-area120-tables/compare/v0.4.1...v0.4.2) (2021-07-26)
 
 
 ### Bug Fixes
@@ -78,7 +78,7 @@
 
 * release as 0.4.2 ([#74](https://www.github.com/googleapis/python-area120-tables/issues/74)) ([682d5dd](https://www.github.com/googleapis/python-area120-tables/commit/682d5dd57c6f752595401bd2d5d232f875bc163b))
 
-### [0.4.1](https://www.github.com/googleapis/python-area120-tables/compare/v0.4.0...v0.4.1) (2021-06-30)
+## [0.4.1](https://www.github.com/googleapis/python-area120-tables/compare/v0.4.0...v0.4.1) (2021-06-30)
 
 
 ### Bug Fixes
@@ -98,7 +98,7 @@
 
 * omit mention of Python 2.7 in 'CONTRIBUTING.rst' ([#1127](https://www.github.com/googleapis/python-area120-tables/issues/1127)) ([#56](https://www.github.com/googleapis/python-area120-tables/issues/56)) ([4bf2bae](https://www.github.com/googleapis/python-area120-tables/commit/4bf2baea55b617393487c2ae6866f04ef073378d)), closes [#1126](https://www.github.com/googleapis/python-area120-tables/issues/1126)
 
-### [0.3.1](https://www.github.com/googleapis/python-area120-tables/compare/v0.3.0...v0.3.1) (2021-06-16)
+## [0.3.1](https://www.github.com/googleapis/python-area120-tables/compare/v0.3.0...v0.3.1) (2021-06-16)
 
 
 ### Bug Fixes