Fix TS compilation error

[thejoeejoee]

TS error: Statements are not allowed in ambient contexts:

ERROR in node_modules/vue-rough-notation/types/VueRoughNotation.d.ts(12,2):
12:2 Statements are not allowed in ambient contexts.
    10 |     padding?: number;
    11 |     iterations?: number;
  > 12 | };
       |  ^
    13 | 
    14 | export interface VueRoughNotationPluginObject extends PluginObject<VueRoughNotationOptions> {
    15 | };
ℹ Version: typescript 3.8.3

vue-rough-notation@0.1.8

[Leecason]

Thank you!😁