feat: upgrade markdown-it to 10.0.0 for supporting em in strong tag

for example: ex***amp***le
markdown-it/markdown-it@e519e6a
commonmark/commonmark-spec@83ed53e

Signed-off-by: Max Wu <jackymaxj@gmail.com>

Author: jackycute

package-lock.json

@@ -82,7 +82,7 @@
     "list.js": "~1.5.0",
     "lodash": "~4.17.15",
     "lutim": "~1.0.2",
-    "markdown-it": "~9.0.1",
+    "markdown-it": "~10.0.0",
     "markdown-it-abbr": "~1.0.4",
     "markdown-it-container": "~2.0.0",
     "markdown-it-deflist": "~2.0.3",