🐛 FIX: Fix to stop stripping of first line in MyST content (#165)

Co-authored-by: Ryo Takahashi <reiyw.setuve@gmail.com>

Author: foster999

sphinx_tabs/tabs.py

@@ -184,7 +184,7 @@ def run(self):
         else:
             panel["hidden"] = "true"
 
-        self.state.nested_parse(self.content[2:], self.content_offset, panel)
+        self.state.nested_parse(self.content[1:], self.content_offset, panel)
 
         if self.env.app.builder.name not in get_compatible_builders(self.env.app):
             # Use base docutils classes
@@ -194,7 +194,7 @@ def run(self):
             panel = nodes.container()
 
             self.state.nested_parse(self.content[0:1], 0, tab_name)
-            self.state.nested_parse(self.content[2:], self.content_offset, panel)
+            self.state.nested_parse(self.content[1:], self.content_offset, panel)
 
             tab += tab_name
             outer_node += tab