feat: add index types and reduce duplication

---
type: pre_commit_static_analysis_report
description: Results of running static analysis checks when committing changes.
report:
  - task: lint_filenames
    status: passed
  - task: lint_editorconfig
    status: passed
  - task: lint_markdown
    status: na
  - task: lint_package_json
    status: na
  - task: lint_repl_help
    status: na
  - task: lint_javascript_src
    status: na
  - task: lint_javascript_cli
    status: na
  - task: lint_javascript_examples
    status: na
  - task: lint_javascript_tests
    status: na
  - task: lint_javascript_benchmarks
    status: na
  - task: lint_python
    status: na
  - task: lint_r
    status: na
  - task: lint_c_src
    status: na
  - task: lint_c_examples
    status: na
  - task: lint_c_benchmarks
    status: na
  - task: lint_c_tests_fixtures
    status: na
  - task: lint_shell
    status: na
  - task: lint_typescript_declarations
    status: na
  - task: lint_typescript_tests
    status: na
  - task: lint_license_headers
    status: passed
---

Author: kgryte

lib/node_modules/@stdlib/types/index.d.ts

@@ -3550,6 +3550,11 @@ declare module '@stdlib/types/ndarray' {
 	*/
 	type BooleanAndGenericDataTypeMap<T> = Remap<BooleanDataTypeMap & { 'generic': genericndarray<T> }>;
 
+	/**
+	* Integer index ndarray kinds.
+	*/
+	type IndexArrayKinds = '' | 'cartesian' | 'linear';
+
 	/**
 	* Boolean index ndarray.
 	*/
@@ -3570,11 +3575,26 @@ declare module '@stdlib/types/ndarray' {
 	*/
 	type TypedIndexArray = uint8ndarray | booleanndarray | int32ndarray;
 
+	/**
+	* Integer index ndarray.
+	*/
+	type IntegerIndexArray = int32ndarray | GenericIntegerIndexArray;
+
 	/**
 	* Index ndarray.
 	*/
 	type IndexArray = GenericIndexArray | TypedIndexArray;
 
+	/**
+	* Cartesian index ndarray.
+	*/
+	type CartesianIndexArray = IntegerIndexArray;
+
+	/**
+	* Linear index ndarray.
+	*/
+	type LinearIndexArray = IntegerIndexArray;
+
 	/**
 	* Interface describing an ndarray index object.
 	*/
@@ -3602,7 +3622,7 @@ declare module '@stdlib/types/ndarray' {
 		/**
 		* Read-only property returning the ndarray index "kind".
 		*/
-		kind: '' | 'cartesian' | 'linear';
+		kind: IndexArrayKinds;
 
 		/**
 		* Read-only property returning the ndarray index type.
@@ -3679,7 +3699,7 @@ declare module '@stdlib/types/ndarray' {
 		/**
 		* Read-only property returning the ndarray index "kind".
 		*/
-		kind: '' | 'cartesian' | 'linear';
+		kind: IndexArrayKinds;
 
 		/**
 		* Read-only property returning the underlying index ndarray data type.
@@ -3749,7 +3769,7 @@ declare module '@stdlib/types/ndarray' {
 		/**
 		* Read-only property returning the ndarray index "kind".
 		*/
-		kind: '' | 'cartesian' | 'linear';
+		kind: IndexArrayKinds;
 
 		/**
 		* Read-only property returning the underlying index ndarray data type.
@@ -3799,7 +3819,7 @@ declare module '@stdlib/types/ndarray' {
 		/**
 		* The index ndarray "kind".
 		*/
-		kind: '' | 'cartesian' | 'linear';
+		kind: IndexArrayKinds;
 
 		/**
 		* The type of index ndarray.
@@ -3874,7 +3894,7 @@ declare module '@stdlib/types/ndarray' {
 		/**
 		* The index ndarray "kind".
 		*/
-		kind: '' | 'cartesian' | 'linear';
+		kind: IndexArrayKinds;
 
 		/**
 		* The type of index ndarray.
@@ -3919,7 +3939,7 @@ declare module '@stdlib/types/ndarray' {
 		/**
 		* The index ndarray "kind".
 		*/
-		kind: '' | 'cartesian' | 'linear';
+		kind: IndexArrayKinds;
 
 		/**
 		* The type of index ndarray.