fix peer node cmd preamble/postscript

This CR updates the preamble and postscript associated
with peer node cmd doc.

FAB-16218 #done

Change-Id: I9e56b1f71f0845240e11083518f79c93084fa5d4
Signed-off-by: senthil <cendhu@gmail.com>

Author: cendhu

docs/source/commands/peernode.md

@@ -1,12 +1,16 @@
 # peer node
 
-The `peer node` command allows an administrator to start a peer node.
+The `peer node` command allows an administrator to start a peer node,
+reset all channels in a peer to the genesis block, or rollback a
+channel to a given block number.
 
 ## Syntax
 
-The `peer node` command has the following subcommand:
+The `peer node` command has the following subcommands:
 
   * start
+  * reset
+  * rollback
 
 ## peer node start
 ```
@@ -60,4 +64,22 @@ starts a peer node in chaincode development mode. Normally chaincode containers
 and maintained by peer. However in chaincode development mode, chaincode is built and started by the user. This mode is useful during chaincode development phase for iterative development.
 See more information on development mode in the [chaincode tutorial](../chaincode4ade.html).
 
+### peer node reset example
+
+```
+peer node reset
+```
+
+resets all channels in the peer to the genesis block, i.e., the first block in the channel. The command also records the pre-reset height of each channel in the file system. Note that the peer process should be stopped while executing this command. If the peer process is running, this command detects that and returns an error instead of performing the reset. When the peer is started after performing the reset, the peer will fetch the blocks for each channel which were removed by the reset command (either from other peers or orderers) and commit the blocks up to the pre-reset height. Until all channels reach the pre-reset height, the peer will not endorse any transactions.
+
+### peer node rollback example
+
+The following command:
+
+```
+peer node rollback -c ch1 -b 150
+```
+
+rolls back the channel ch1 to block number 150. The command also records the pre-rolled back height of channel ch1 in the file system. Note that the peer should be stopped while executing this command. If the peer process is running, this command detects that and returns an error instead of performing the rollback. When the peer is started after performing the rollback, the peer will fetch the blocks for channel ch1 which were removed by the rollback command (either from other peers or orderers) and commit the blocks up to the pre-rolled back height. Until the channel ch1 reaches the pre-rolled back height, the peer will not endorse any transaction for any channel.
+
 <a rel="license" href="http://creativecommons.org/licenses/by/4.0/"><img alt="Creative Commons License" style="border-width:0" src="https://i.creativecommons.org/l/by/4.0/88x31.png" /></a><br />This work is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution 4.0 International License</a>.

docs/wrappers/peer_node_postscript.md

@@ -12,4 +12,22 @@ starts a peer node in chaincode development mode. Normally chaincode containers
 and maintained by peer. However in chaincode development mode, chaincode is built and started by the user. This mode is useful during chaincode development phase for iterative development.
 See more information on development mode in the [chaincode tutorial](../chaincode4ade.html).
 
+### peer node reset example
+
+```
+peer node reset
+```
+
+resets all channels in the peer to the genesis block, i.e., the first block in the channel. The command also records the pre-reset height of each channel in the file system. Note that the peer process should be stopped while executing this command. If the peer process is running, this command detects that and returns an error instead of performing the reset. When the peer is started after performing the reset, the peer will fetch the blocks for each channel which were removed by the reset command (either from other peers or orderers) and commit the blocks up to the pre-reset height. Until all channels reach the pre-reset height, the peer will not endorse any transactions.
+
+### peer node rollback example
+
+The following command:
+
+```
+peer node rollback -c ch1 -b 150
+```
+
+rolls back the channel ch1 to block number 150. The command also records the pre-rolled back height of channel ch1 in the file system. Note that the peer should be stopped while executing this command. If the peer process is running, this command detects that and returns an error instead of performing the rollback. When the peer is started after performing the rollback, the peer will fetch the blocks for channel ch1 which were removed by the rollback command (either from other peers or orderers) and commit the blocks up to the pre-rolled back height. Until the channel ch1 reaches the pre-rolled back height, the peer will not endorse any transaction for any channel.
+
 <a rel="license" href="http://creativecommons.org/licenses/by/4.0/"><img alt="Creative Commons License" style="border-width:0" src="https://i.creativecommons.org/l/by/4.0/88x31.png" /></a><br />This work is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution 4.0 International License</a>.

docs/wrappers/peer_node_preamble.md

@@ -1,9 +1,13 @@
 # peer node
 
-The `peer node` command allows an administrator to start a peer node.
+The `peer node` command allows an administrator to start a peer node,
+reset all channels in a peer to the genesis block, or rollback a
+channel to a given block number.
 
 ## Syntax
 
-The `peer node` command has the following subcommand:
+The `peer node` command has the following subcommands:
 
   * start
+  * reset
+  * rollback