Fixed links to prerequisits by adding anchor and pointing to that instead of section title.

Signed-off-by: Philip Windecker <philip.windecker@avenyr.de>

Author: philipwindecker

doc/setup/installing_linux_cpp.adoc

@@ -6,7 +6,7 @@ endif::[]
 
 **Prerequisites**
 
-* You have installed everything described in <<Installing _protobuf_ for static / dynamic linking depending on the use case>>.
+* You have installed everything described in <<top-installing-osi-prerequisits>>.
 
 **Steps**
 

doc/setup/installing_linux_python.adoc

@@ -6,7 +6,7 @@ endif::[]
 
 **Prerequisites**
 
-* You have installed everything described in <<Installing _protobuf_ for static / dynamic linking depending on the use case>>.
+* You have installed everything described in <<top-installing-osi-prerequisits>>.
 * You have installed _pip3_.
 * You have installed _python-setuptools_.
 * For a local installation, you have installed _virtualenv_.

doc/setup/installing_prerequisites.adoc

@@ -2,7 +2,7 @@ ifndef::include-only-once[]
 :root-path: ../
 include::{root-path}_config.adoc[]
 endif::[]
-
+[#top-installing-osi-prerequisits]
 = Installing _protobuf_ for static / dynamic linking
 
 == Prerequisites

doc/setup/installing_windows_cpp.adoc

@@ -6,7 +6,7 @@ endif::[]
 
 **Prerequisites**
 
-* You have installed everything described in <<Installing _protobuf_ for static / dynamic linking depending on the use case>>.
+* You have installed everything described in <<top-installing-osi-prerequisits>>.
 
 **Steps**
 

doc/setup/installing_windows_python.adoc

@@ -6,7 +6,7 @@ endif::[]
 
 **Prerequisites**
 
-* You have installed everything described in <<Installing _protobuf_ for static / dynamic linking depending on the use case>>.
+* You have installed everything described in <<top-installing-osi-prerequisits>>.
 * You have installed _Python_ with administrator rights.
 * Make sure _Python_ is added to `PATH`.