Refactoring lo.IntersectBy + adding loit.IntersectBy + adding doc (#739)

* feat(intersectby): form transform callback in first position and add support for vaarg

* feat(it): adding loit.IntersectBy

* doc: adding lo.IntersectBy + loit.IntersectBy

* doc: adding lo.IntersectBy + loit.IntersectBy

* style: fix linter

* doc: adding example for lo.IntersectBy

docs/data/core-intersectby.md

@@ -0,0 +1,32 @@
+---
+name: IntersectBy
+slug: intersectby
+sourceRef: intersect.go#L174
+category: core
+subCategory: intersect
+playUrl:
+variantHelpers:
+  - core#intersect#intersectby
+similarHelpers:
+  - core#intersect#intersect
+  - it#intersect#intersect
+  - it#intersect#intersectby
+  - core#intersect#difference
+  - core#intersect#union
+  - core#intersect#without
+  - core#slice#uniq
+position: 80
+signatures:
+  - "func IntersectBy[T any, K comparable, Slice ~[]T](transform func(T) K, lists ...Slice) Slice"
+---
+
+Returns the intersection between two collections using a custom key selector function.
+
+```go
+transform := func(v int) string {
+  return strconv.Itoa(v)
+}
+
+lo.IntersectBy(transform, []int{0, 3, 5, 7}, []int{3, 5}, []int{0, 1, 2, 0, 3, 0})
+// []int{3}
+```