Global edge index documentation (#1253)

* Add global edge index documentation

* Add dropping of global edge index

* Apply suggestions from code review

* update

---------

Co-authored-by: Matea Pesic <80577904+matea16@users.noreply.github.com>
Co-authored-by: matea16 <mateapesic@hotmail.com>

Author: Josipmrden

pages/fundamentals/indexes.mdx

@@ -306,6 +306,30 @@ Named parameters are not supported for edge-type property indexes.
 
 </Callout>
 
+### Global edge property index
+
+Since edges can have only one edge type, Memgraph provides a way to index all the edges that contain
+a certain property via the global edge index. The syntax to index all the edges that have a certain property is
+the following:
+
+```cypher
+CREATE GLOBAL EDGE INDEX ON :(property_name);
+```
+
+Creating a global edge property index will optimize the following type of queries:
+
+```cypher
+MATCH ()-[r {property_name: value}]->() RETURN r;
+```
+
+<Callout type="info">
+
+If you need to access nodes of found edges, you can use the `startNode(r)` and `endNode(r)` functions.
+
+Named parameters are not supported for edge-type property indexes.
+
+</Callout>
+
 ### Point index
 
 Point index can be utilized for more performant spatial queries which use `WHERE point.distance()` or `WHERE point.withinbbox()`.
@@ -447,6 +471,14 @@ DROP INDEX ON :Label(property1, property2);
 DROP EDGE INDEX ON :EDGE_TYPE;
 ```
 
+```cypher
+DROP EDGE INDEX ON :EDGE_TYPE(property_name);
+```
+
+```cypher
+DROP GLOBAL EDGE INDEX ON :(property_name);
+```
+
 These queries instruct all active transactions to abort as soon as possible.
 Once all transactions have finished, the index will be deleted.