[README.md] Update installation steps (sonic-net#730)

Updated installation steps
Added missing required packages

Signed-off-by: Alexandru Banu <Alexandru.Banu@metaswitch.com>

README.md

@@ -23,12 +23,10 @@ Install dependencies:
 
     sudo apt-get install redis-server -t trusty
     sudo apt-get install libhiredis0.13 -t trusty
-    
+
 Install building dependencies:
 
-    sudo apt-get install libtool
-    sudo apt-get install autoconf automake
-    sudo apt-get install dh-exec
+    sudo apt-get install libtool autoconf dh-exec
 
 There are a few different ways you can install sairedis.
 
@@ -49,7 +47,13 @@ Get ASIC SDK and SAI packages from your ASIC vendor and install them.
 
 Install prerequisite packages:
 
-    sudo apt-get install libswsscommon libswsscommon-dev
+    sudo apt-get install libswsscommon libswsscommon-dev libhiredis-dev libzmq3-dev libpython-dev
+
+Note: libswsscommon-dev requires libnl-3-200-dev, libnl-route-3-200-dev and libnl-nf-3-200-dev version >= 3.5.0. If these are not available via apt repositories, you can get them from the latest sonic-buildimage Jenkins build: https://sonic-jenkins.westus2.cloudapp.azure.com/job/vs/job/buildimage-vs-all/lastSuccessfulBuild/artifact/target/debs/buster/.
+
+Install SAI dependencies:
+
+    sudo apt-get install doxygen graphviz aspell
 
 You can compile and install from source using:
 
@@ -62,6 +66,11 @@ You can also build a debian package using:
     ./autogen.sh
     fakeroot debian/rules binary
 
+If you do not have libsai, you can build a debian package using:
+
+    ./autogen.sh
+    fakeroot debian/rules binary-syncd-vs
+
 ## Need Help?
 
 For general questions, setup help, or troubleshooting: