feat: add typescript definitions (#54)

Add TypeScript definition file

index.d.ts

@@ -0,0 +1,47 @@
+// Type definitions for styled-css-grid
+// Project: https://github.com/azz/styled-css-grid
+// Definitions by: protocol114 <https://github.com/protocol114>
+
+declare module 'styled-css-grid' {
+    import * as React from "react";
+    import {StyledComponent} from "styled-components";
+
+    export interface ICellProps extends React.ComponentPropsWithRef<'div'> {
+        className?: string,
+        width?: number,
+        height?: number,
+        top?: number | string,
+        left?: number | string,
+        middle?: boolean,
+        center?: boolean,
+        area?: string
+    }
+
+    export interface IGridProps extends React.ComponentPropsWithRef<'div'> {
+        className?: string,
+        columns?: number | string,
+        gap?: string,
+        columnGap?: string,
+        rowGap?: string,
+        height?: string,
+        minRowHeight?: string,
+        flow?: string,
+        rows?: number | string,
+        areas?: string[],
+        justifyContent?: string,
+        alignContent?: string
+    }
+
+    export type GridComponent = StyledComponent<
+        React.ForwardRefExoticComponent<Partial<IGridProps>>,
+        any
+    >;
+
+    export type CellComponent = StyledComponent<
+        React.ForwardRefExoticComponent<Partial<ICellProps>>,
+        any
+    >;
+
+    export const Grid: GridComponent;
+    export const Cell: CellComponent;
+}