How to write multi-level (bullet) lists in a table using rmarkdown and pandoc

I am looking to create a table in a PDF document using rmarkdown, knitr and pander. I am able to create a simple bullet list but now require another level in that list. In the table shown below, I require the "Rave reviews" bullet to be a sub-bullet of the "Offers workshops..." bullet.

The issue I'm having pertains to the line of code below in the mytable dataframe in the Description column. Although I attempt to create the 4 spaces required for a sub-bullet using \x20[1], those spaces do not appear - and hence no sub-bullets (although no error is shown). I also tried the most obvious way of simply adding in 4 spaces in the code to no avail. Also attempted to set my R options to include strip.white = FALSE, but that has also not proven helpful (see below).

---
title: "xxx"
author: "xxx"
output:
  pdf_document:
    fig_height: 4
    fig_width: 10
    highlight: tango
  word_document: default
geometry: margin=3cm
---

```{r global_options, include=FALSE, echo=FALSE}
require(knitr)
opts_chunk$set(fig.width=8, fig.height=4, fig.path='figs/', dpi=500,
               echo=FALSE, warning=FALSE, message=FALSE, results='hide', strip.white = FALSE)
```

```{r pandoc_options, include=FALSE, echo=FALSE}
require(pander)
panderOptions('digits', 3)
panderOptions('round', 3)
panderOptions('keep.trailing.zeros', TRUE)
panderOptions('keep.line.breaks', TRUE)
```

```{r concepts, echo=FALSE}
mytable = data.frame(
    Concept     = c("Decoded", "XXX"),
    Description = c("* Founded in 2011\ \n* Offers workshops to take people from zero skills and knowledge in programming through to coding a multi-platform app using HTML, CSS and Javascript in a single day\ \n\x20\x20\x20\x20+ Rave reviews", "XXX"),
    Website     = c("http://decoded.com/uk/","XXX"))
```

``` {r concepts_descriptions, results = 'asis'}
pander::pander(mytable, keep.line.breaks = TRUE, style = 'grid', justify = 'left')
```

References

[1] I got the \x20 hint from here, after attempting \\s, \s, \ \s, \\\s, etc. to no avail (suggested here).

You can nest the items inside the bullet:

```{r concepts, echo=FALSE}
mytable = data.frame(
    Concept     = c("Decoded", "XXX"),
    Description = c("* Founded in 2011\ \n
    * Offers workshops to take people from zero skills and knowledge in programming through to coding a multi-platform app using HTML, CSS and Javascript in a single day\ \n
    \\begin{itemize}
      \\item Rave reviews \n
      \\item e.t.c
    \\end{itemize}", "XXX"),
    Website     = c("http://decoded.com/uk/","XXX"))
```