message: test(md-enhance): fix demo
diff: @@ -51,10 +51,6 @@ $$
  = \left(\frac {y^{\omega}} {\omega}\right) \left\{(\log y)^r + \sum_{i=1}^r \frac {(-1)^ Ir \cdots (r-i+1) (\log y)^{ri}} {\omega^i} \right\}
  $$
  -## Playground
  -
  -<KatexPlayground />
  -
  ## Tutorial
  ### Operator
  