dev-readme: Fix formatting of initdb command

Change-Id: Ifb127a41af449f9558c8e7e55d7f90616823a72a
Signed-off-by: Shawn O. Pearce <sop@google.com>

Documentation/dev-readme.txt

@@ -64,10 +64,10 @@ PostgreSQL Setup
 
 Initialize and start PostgreSQL (where $data is the location of your data):
 
-===
+====
   initdb --locale en_US.UTF-8 -D $data
   postmaster -D $data >/tmp/logfile 2>&1 &
-===
+====
 
 Create the JDBC user as a normal user (no superuser access) and
 assign it an encrypted password: