[docs] Add curl to installed packages in README.md
The build_docs.py script will invoke curl to fetch a suitable hugo
binary, ensure that the docs mention it as required.
Signed-off-by: Garret Kelly <gdk@google.com>
diff --git a/README.md b/README.md
index 01bcac2..851a5e7 100644
--- a/README.md
+++ b/README.md
@@ -30,7 +30,7 @@
in the repository root):
```command
-$ sudo apt install python3 python3-pip
+$ sudo apt install curl python3 python3-pip
$ pip3 install --user -r python-requirements.txt
```