How to group rows in a dataframe by quarters?

I have a dataframe with 213 rows and 2 columns (Date and Article). The final aim is to reduce the number of rows by grouping the Date by quarterly. Obviously, I want texts from the Article column to be merged accordingly.

Let's take an example.

Date <- c("2000-01-05", "2000-02-03", "2000-03-02", "2000-03-30", "2000-04-13", "2000-05-11", "2000-06-08", "2000-07-06", "2000-09-14", "2000-10-05", "2000-10-19", "2000-11-02", "2000-12-14")
Article <- c("Long Text","Long Text","Long Text","Long Text","Long Text","Long Text","Long Text","Long Text","Long Text","Long Text","Long Text","Long Text","Long Text")

Date <- data.frame(Date)
Article <- data.frame(Article)

df <- cbind(Date, Article)

#Dataframe

Date           Article
1  2000-01-05 Long Text
2  2000-02-03 Long Text
3  2000-03-02 Long Text
4  2000-03-30 Long Text
5  2000-04-13 Long Text
6  2000-05-11 Long Text
7  2000-06-08 Long Text
8  2000-07-06 Long Text
9  2000-09-14 Long Text
10 2000-10-05 Long Text
11 2000-10-19 Long Text
12 2000-11-02 Long Text
13 2000-12-14 Long Text

The final output I would like to obtain is the following:

Date         Article
1  2000 Q1   Long Text, Long Text, Long Text, Long Text
2  2000 Q2   Long Text, Long Text, Long Text
3  2000 Q3   Long Text, Long Text
4  2000 Q4   Long Text, Long Text, Long Text, Long Text

Essentially, the rows have been grouped together by quarters as well as the corresponding text.

I tried to look around but I have no idea how to do it, unofrtunately.

Can anyone help me out?

Thanks!