如何在Rmarkdown HTML文档中正确呈现表格

Question

此处是初学者R用户。当我使用Knitr制作HTML文档时，表的显示方式与从R脚本运行R代码时的显示方式相同，而不是从R笔记本运行时的外观。看起来像image1，而不是image2 如何才能“正确”显示表格？如果不能这样做，是否可以将不间断的空格字符（＆nbsp;）更改为“普通”空格（“”）？

这是我的代码

set.seed(42)
library(magrittr)
library(qwraps2)
library(markdown)
library(knitr)

# define the markup language we are working in.
# options(qwraps2_markup = "latex") is also supported.
options(qwraps2_markup = "markdown")

data(mtcars)

mtcars2 <-
  dplyr::mutate(mtcars,
                cyl_factor = factor(cyl,
                                    levels = c(6, 4, 8),
                                    labels = paste(c(6, 4, 8), "cylinders")),
                cyl_character = paste(cyl, "cylinders"))

our_summary1 <-
  list("Miles Per Gallon" =
       list("min" = ~ min(.data$mpg),
            "max" = ~ max(.data$mpg),
            "mean (sd)" = ~ qwraps2::mean_sd(.data$mpg)),
       "Displacement" =
       list("min" = ~ min(.data$disp),
            "median" = ~ median(.data$disp),
            "max" = ~ max(.data$disp),
            "mean (sd)" = ~ qwraps2::mean_sd(.data$disp)),
       "Weight (1000 lbs)" =
       list("min" = ~ min(.data$wt),
            "max" = ~ max(.data$wt),
            "mean (sd)" = ~ qwraps2::mean_sd(.data$wt)),
       "Forward Gears" =
       list("Three" = ~ qwraps2::n_perc0(.data$gear == 3),
            "Four"  = ~ qwraps2::n_perc0(.data$gear == 4),
            "Five"  = ~ qwraps2::n_perc0(.data$gear == 5))
       )

whole <- summary_table(mtcars2, our_summary1)
whole

R版本和加载的软件包，以防发现我犯的错误：

               _                           
platform       x86_64-w64-mingw32          
arch           x86_64                      
os             mingw32                     
system         x86_64, mingw32             
status                                     
major          3                           
minor          6.3                         
year           2020                        
month          02                          
day            29                          
svn rev        77875                       
language       R                           
version.string R version 3.6.3 (2020-02-29)
nickname       Holding the Windsock        
 [1] "markdown"  "devtools"  "usethis"   "rmarkdown" "knitr"     "qwraps2"  
 [7] "magrittr"  "haven"     "forcats"   "stringr"   "dplyr"     "purrr"    
[13] "readr"     "tidyr"     "tibble"    "ggplot2"   "tidyverse" "rstatix"