fix format

docs/manual-EN/1.overview/1.concepts/2.nGQL-overview.md

@@ -37,7 +37,7 @@
   - ***Edge type (ET)*** is a human readable string, internally it will be assigned a 32-bit integer. The edge type decides the property list (schema) on the edge
   - ***Edge rank*** is an immutable user-assigned 64-bit signed integer. It affects the edge order between two vertices. The edge with a higher rank value comes first. When not specified, the default rank value is zero.
   - Each edge can only be of one type
-- **Path** : A ***non-forked*** connection with multiple vertices and edges between them
+- **Path** : A _non-forked_ connection with multiple vertices and edges between them
   - The length of a path is the number of the edges on the path, which is one less than the number of vertices
   - A path can be represented by a list of vertices, edge types, and rank. An edge is a special path with length==1