remove support for dollar surrounding backtick

src/lib.rs

@@ -643,9 +643,6 @@ where
             let check = if checked { "x" } else { " " };
             write!(formatter, "[{}] ", check)
         }
-        InlineMath(ref text) if text.contains(r"\$") && (text.starts_with('`').not() && text.ends_with('`').not()) => {
-            write!(formatter, "$`{}`$", text)
-        }
         InlineMath(ref text) => write!(formatter, "${}$", text),
         DisplayMath(ref text) => write!(formatter, "$${}$$", text),
     }

tests/display.rs

@@ -317,7 +317,7 @@ fn math() {
         s(Event::InlineMath(r##"\sqrt{3x-1}+(1+x)^2"##.into())),
         r##"$\sqrt{3x-1}+(1+x)^2$"##
     );
-    assert_eq!(s(Event::InlineMath(r##"\sqrt{\$4}"##.into())), r##"$`\sqrt{\$4}`$"##);
+    assert_eq!(s(Event::InlineMath(r##"\sqrt{\$4}"##.into())), r##"$\sqrt{\$4}$"##);
     assert_eq!(s(
       Event::DisplayMath(
         r##"\left( \sum_{k=1}^n a_k b_k \right)^2 \leq \left( \sum_{k=1}^n a_k^2 \right) \left( \sum_{k=1}^n b_k^2 \right)"##.into()

tests/fixtures/snapshots/stupicat-math-output

@@ -68,7 +68,7 @@ either$
 
 `$` character can be escaped with backslash in mathematical expressions:
 
-$`\$`$
+$\$$
 
 $$y = \$ x$$
 
@@ -213,7 +213,7 @@ $$$$\\text{first $$ second}$$
 
 Dollar signs must also be backslash-escaped if they occur within math:
 
-$`\text{\$}`$
+$\text{\$}$
 
 $$x$x$$
 
@@ -327,7 +327,7 @@ $$ x = {-b \pm \sqrt{b^2-4ac} \over 2a} $$
 
 Spacing around dollar sign in math mode
 
-$`x = \$`$
+$x = \$$
 
 Math in italic text