don't add a td if it's only used for styling

src/paragraph/parser/mod.rs

@@ -297,15 +297,19 @@ pub(crate) struct Td {
     absatz: Absatz,
 }
 impl Td {
-    pub(crate) fn parse(n: &Node) -> Self {
+    /// Returns `None` if td doesn't contain anything. used e.g. in § 71b to style table...
+    pub(crate) fn parse(n: &Node) -> Option<Self> {
         Expect::from(n).tag("td");
 
         let mut c = n.children();
-        let absatz = Absatz::parse(c.next().unwrap());
+
+        let Some(next) = c.next() else { return None };
+
+        let absatz = Absatz::parse(next);
 
         Expect::empty(c.next());
 
-        Self { absatz }
+        Some(Self { absatz })
     }
 }
 
@@ -320,7 +324,9 @@ impl Tr {
         let mut tds = Vec::new();
 
         for child in n.children() {
-            tds.push(Td::parse(&child));
+            if let Some(td) = Td::parse(&child) {
+                tds.push(td);
+            }
         }
 
         Self { tds }