refactor: Various cleanup (#11)

* refactor: interface for commit message analyzer

* refactor: interface for versioning strategy

* refactor(releasepr): rebuild pr description

Build PR description from scratch and parsed values instead of copying some of the AST to next description.

releasepr.md.tpl

@@ -1,29 +1,32 @@
----
-
 <!-- section-start changelog -->
 {{ .Changelog }}
 <!-- section-end changelog -->
 
 ---
 
-## releaser-pleaser Instructions
-{{ if .Overrides }}
-{{- .Overrides -}}
-{{- else }}
-<!-- section-start overrides -->
-> If you want to modify the proposed release, add you overrides here. You can learn more about the options in the docs.
+<details>
+  <summary><h4>PR by <a href="https://github.com/apricote/releaser-pleaser">releaser-pleaser</a> 🤖</h4></summary>
 
-### Prefix
+If you want to modify the proposed release, add you overrides here. You can learn more about the options in the docs.
+
+## Release Notes
+
+### Prefix / Start
+
+This will be added to the start of the release notes.
 
 ```rp-prefix
+{{- if .Overrides.Prefix }}
+{{ .Overrides.Prefix }}{{ end }}
 ```
 
-### Suffix
+### Suffix / End
+
+This will be added to the end of the release notes.
 
 ```rp-suffix
+{{- if .Overrides.Suffix }}
+{{ .Overrides.Suffix }}{{ end }}
 ```
 
-<!-- section-end overrides -->
-
-{{ end }}
-#### PR by [releaser-pleaser](https://github.com/apricote/releaser-pleaser)
+</details>