fix: add uni.scss $uni-font-size-lg px (#34)

Author: FliPPeDround

src/uni.scss

@@ -41,7 +41,7 @@ $uni-border-color: #c8c7cc;
 /* 文字尺寸 */
 $uni-font-size-sm: 12px;
 $uni-font-size-base: 14px;
-$uni-font-size-lg: 16;
+$uni-font-size-lg: 16px;
 
 /* 图片尺寸 */
 $uni-img-size-sm: 20px;
@@ -73,4 +73,4 @@ $uni-font-size-title: 20px;
 $uni-color-subtitle: #555; // 二级标题颜色
 $uni-font-size-subtitle: 18px;
 $uni-color-paragraph: #3f536e; // 文章段落颜色
-$uni-font-size-paragraph: 15px;
+$uni-font-size-paragraph: 15px;