feat(conventional): parse body and footers according to the rules

Previous assumption about multiple labeled body blocks and footers is
not correct. There is only one body text block with multi-line support.
A footer always starts with a token with a separator.
- A body ends when a footer is found or text ends.
- A footer ends when another footer is found or text ends.

pkg/config/config_test.go

@@ -100,7 +100,7 @@ github:
 				Compress: false}},
 		ReleaseTitle: "go-semantic-release release",
 		IsPreRelease: false,
-		Analyzer: config.AnalyzerConfig{BlockPrefixes: []string{}},
+		Analyzer: config.AnalyzerConfig{TokenSeparators: []string{}},
 	}, result)
 
 }