Since you're using HTML, you can use the AnchorJS library to do what you need.
Create a file with the following code (I saved it as anchor.html). Also, make sure to read the documentation to see how to use the library.
<script src='https://cdnjs.cloudflare.com/ajax/libs/anchor-js/4.2.0/anchor.js'></script>
<script>
anchors.add();
</script>
In the yaml header of your R Markdown document, include the above file after your body using includes (documented in the R Markdown book. Make sure the anchor.html is in the same folder as your .Rmd file:
---
title: "Anchored Links"
output:
html_document:
includes:
after_body: anchor.html
---
So using the example Rmd created by RStudio, this is what your Rmd file should look like:
---
title: "Anchored Links"
output:
html_document:
includes:
after_body: anchor.html
---
```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```
## R Markdown
This is an R Markdown document. Markdown is a simple formatting syntax for authoring HTML, PDF, and MS Word documents. For more details on using R Markdown see <http://rmarkdown.rstudio.com>.
When you click the **Knit** button a document will be generated that includes both content as well as the output of any embedded R code chunks within the document. You can embed an R code chunk like this:
```{r cars}
summary(cars)
```
## Including Plots
You can also embed plots, for example:
```{r pressure, echo=FALSE}
plot(pressure)
```
Note that the `echo = FALSE` parameter was added to the code chunk to prevent printing of the R code that generated the plot.
And the output: