Minor copyediting on sample installation steps

Fixed a small typo and ensured consistency of whitespace etc.

README.amazon_linux

@@ -5,7 +5,7 @@ sudo vim /etc/hosts
 # add mount points
 sudo vim /etc/fstab
 
-#install packages
+# install packages
 sudo yum install git
 sudo yum install gcc
 sudo yum install readline-devel
@@ -16,21 +16,21 @@ sudo yum install bison
 sudo yum install flex
 sudo yum install gcc-c++
 
-#edit sysctl
+# edit sysctl
 vm.overcommit_memory = 2
 
-#edit  /etc/security/limits.conf
+# edit /etc/security/limits.conf
 * soft core unlimited
 * soft nofile 65536
 * hard nofile 65536
 * soft nproc 131072
 * hard nproc 131072
 
-#edit /etc/grub.conf
+# edit /etc/grub.conf
 add transparent_hugepage=never to kernel boot command line
 cat /sys/kernel/mm/transparent_hugepage/enabled
 
-#update blockdev read ahead
+# update blockdev read ahead
 /sbin/blockdev --setra 16384 GPDB_DEVICE_NAMES
 
 # configure and build
@@ -39,7 +39,7 @@ make
 sudo make install
 . /usr/local/gpdb/greenplum_path.sh
 
-#python updae
+# python update
 sudo pip install --upgrade pip
 as root
     pip install epydoc
@@ -51,9 +51,9 @@ mkdir primary
 mkdir mirror
 mkdir master
 cp $GPHOME/docs/cli_help/gpconfigs/gpinitsystem_test .
-edit gpinitsystem_test
-    create ./hostlist_singlenode
-    modify directories, etc
+# edit gpinitsystem_test
+create ./hostlist_singlenode
+modify directories, etc
 
 gpssh-exkeys -h `hostname`
 gpinitsystem -c gpinitsystem.config