rar, read, renice, rev, roll, route, rsync: add link (#6929)

pages/common/rar.md

@@ -1,6 +1,7 @@
 # rar
 
 > The RAR archiver. Supports multi-volume archives that can be optionally self-extracting.
+> More information: <https://manned.org/rar>.
 
 - Archive 1 or more files:
 

pages/common/read.md

@@ -1,6 +1,7 @@
 # read
 
 > BASH builtin for retrieving data from standard input.
+> More information: <https://manned.org/read.1p>.
 
 - Store data that you type from the keyboard:
 

pages/common/renice.md

@@ -2,6 +2,7 @@
 
 > Alters the scheduling priority/nicenesses of one or more running processes.
 > Niceness values range from -20 (most favorable to the process) to 19 (least favorable to the process).
+> More information: <https://manned.org/renice>.
 
 - Change priority of a running process:
 

pages/common/rev.md

@@ -1,6 +1,7 @@
 # rev
 
 > Reverse a line of text.
+> More information: <https://manned.org/rev>.
 
 - Reverse the text string "hello":
 

pages/common/roll.md

@@ -1,6 +1,7 @@
 # roll
 
 > Rolls a user-defined dice sequence.
+> More information: <https://manned.org/roll>.
 
 - Roll 3 6-sided dice and sums the results:
 

pages/common/route.md

@@ -1,6 +1,7 @@
 # route
 
 > Use route cmd to set the route table.
+> More information: <https://manned.org/route>.
 
 - Display the information of route table:
 

pages/common/rsync.md

@@ -2,6 +2,7 @@
 
 > Transfer files either to or from a remote host (not between two remote hosts).
 > Can transfer single files, or multiple files matching a pattern.
+> More information: <https://manned.org/rsync>.
 
 - Transfer file from local to remote host: