Add support for custom template path.

src/lib.rs

@@ -289,14 +289,18 @@ fn render_markdown (content: &tera::Value, args: &HashMap<String, tera::Value>)
 
 impl PageRenderer {
     pub fn new() -> PageRenderer {
-        let mut tera = tera::Tera::new("templates/**/*.html").unwrap();
+        Self::with_template_path(DEFAULT_TEMPLATES_PATH)
+    }
+
+    pub fn with_template_path(template_path: &str) -> PageRenderer {
+        let mut tera = tera::Tera::new(&format!("{template_path}/**/*.html")).unwrap();
         tera.register_filter("markdown", render_markdown);
         PageRenderer {
-            template_root: DEFAULT_TEMPLATES_PATH.into(),
+            template_root: template_path.into(),
             tera
         }
     }
-
+    
     pub fn render_page(&self, historian: &Historian, page: &Page, options: &Table) -> String {
         self.render_page_template("page.html", &historian, &page, &options)
     }