improve README

dist/smartstring.base64.d.ts

@@ -19,7 +19,7 @@ export declare class Base64 {
     /**
      * the base64uri encoded version of the original string
      */
-    readonly base64StringUri: any;
+    readonly base64UriString: any;
 }
 export declare let base64: {
     encode: (stringArg: string) => any;

dist/smartstring.base64.js

@@ -31,7 +31,7 @@ class Base64 {
     /**
      * the base64uri encoded version of the original string
      */
-    get base64StringUri() {
+    get base64UriString() {
         return exports.base64.encodeUri(this.refString);
     }
 }