feat(config): make the git section optional (#45)

git-cliff-core/src/commit.rs

@@ -75,7 +75,7 @@ impl Commit<'_> {
 	/// * extacts links and generates URLs
 	pub fn process(&self, config: &GitConfig) -> Result<Self> {
 		let mut commit = self.clone();
-		if config.conventional_commits {
+		if config.conventional_commits.unwrap_or(true) {
 			if config.filter_unconventional.unwrap_or(true) {
 				commit = commit.into_conventional()?;
 			} else if let Ok(conv_commit) = commit.clone().into_conventional() {

git-cliff-core/src/config.rs

@@ -7,6 +7,7 @@ pub struct Config {
 	/// Configuration values about changelog generation.
 	pub changelog: ChangelogConfig,
 	/// Configuration values about git.
+	#[serde(default)]
 	pub git:       GitConfig,
 }
 
@@ -24,10 +25,12 @@ pub struct ChangelogConfig {
 }
 
 /// Git configuration
-#[derive(Debug, Clone, serde_derive::Serialize, serde_derive::Deserialize)]
+#[derive(
+	Debug, Default, Clone, serde_derive::Serialize, serde_derive::Deserialize,
+)]
 pub struct GitConfig {
 	/// Whether to enable parsing conventional commits.
-	pub conventional_commits:  bool,
+	pub conventional_commits:  Option<bool>,
 	/// Whether to filter out unconventional commits.
 	pub filter_unconventional: Option<bool>,
 	/// Git commit parsers.