Clarify documentation of rebalance command

Added some documentation to clarify that lak analyze rebalance command
only prints asset classes that are outside the bounds.

Fixes #44.

docs/lak.md

@@ -1412,8 +1412,8 @@ Options:
 $ lak analyze rebalance --help
 Usage: lak analyze rebalance [OPTIONS]
 
-  Shows if assets needs to be rebalanced based on a band based rebalancing
-  scheme. For more information, please refer to
+  Shows if any asset classes need to be rebalanced based on a band based
+  rebalancing scheme. For more information, please refer to
   https://www.whitecoatinvestor.com/rebalancing-the-525-rule/.
 
 Options:
@@ -1432,6 +1432,15 @@ method. Currently, it also doesn't account for
 be problematic. Taxation is a complex topic and users are _strongly_
 advised to do their own research before using this tool.
 
+The `rebalance` command only shows asset classes that don't fall within
+the rebalancing bands. If all asset classes are within the bands, it prints
+a message to that effect:
+
+```
+$ lak analyze rebalance
+Portfolio Asset allocation within bounds.
+```
+
 ### lak edit
 
 This command is used to edit various parts of the portfolio. The

lakshmi/lak.py

@@ -818,7 +818,7 @@ def tlh(max_percentage, max_dollars):
               show_default=True,
               help='The max relative difference before rebalancing.')
 def rebalance(max_abs_percentage, max_relative_percentage):
-    """Shows if assets needs to be rebalanced based on a band
+    """Shows if any asset classes need to be rebalanced based on a band
     based rebalancing scheme. For more information, please refer to
     https://www.whitecoatinvestor.com/rebalancing-the-525-rule/."""
     global lakctx