feat(components): add md-border custom element

src/components/index.ts

@@ -4,6 +4,7 @@ import "./md-table";
 import "./md-link";
 import "./md-pins";
 import "./md-bg";
+import "./md-border";
 import "./md-font";
 import "./md-embed";
 import "./md-deck";
@@ -26,6 +27,7 @@ export type { DiceProps } from "./md-dice";
 export type { TableProps } from "./md-table";
 export type { BgProps } from "./md-bg";
 export type { FontProps } from "./md-font";
+export type { BorderProps } from "./md-border";
 export type { EmbedProps } from "./md-embed";
 export type { YarnSpinnerProps } from "./md-yarn-spinner";
 export type { TokenProps } from "./md-token";