INSTALL: Mention both asciidoctor and asciidoctor-pdf.

diff --git a/INSTALL b/INSTALL
index 8bf8ef18184577914e98ef31b8603bfe8a98cbaa..edb7940d522c9126e1edcbf8579e1d54fd2762f7 100644 (file)
--- a/INSTALL
+++ b/INSTALL
@@ -26,7 +26,8 @@ Requirements
  - libsigrokcxx >= 0.5.1 (libsigrok C++ bindings)
  - libsigrokdecode >= 0.5.2
  - libsigrokandroidutils >= 0.1.0 (optional, only needed on Android)
- - Asciidoctor (optional, only needed to build the manual)
+ - asciidoctor (optional, only needed to build the HTML manual)
+ - asciidoctor-pdf (optional, only needed to build the PDF manual)
 
 
 Building and installing