bs/cf/is: more informative usage, mention begin date (#518)

hledger/Hledger/Cli/Balancesheet.hs

@@ -11,6 +11,7 @@ module Hledger.Cli.Balancesheet (
  ,tests_Hledger_Cli_Balancesheet
 ) where
 
+import Data.String.Here
 import System.Console.CmdArgs.Explicit
 import Test.HUnit
 
@@ -21,7 +22,11 @@ import Hledger.Cli.BalanceView
 bsBV = BalanceView {
          bvmode     = "balancesheet",
          bvaliases  = ["bs"],
-         bvhelp     = "show a balance sheet",
+         bvhelp     = [here|This command displays a simple balance sheet, showing historical ending
+balances of asset and liability accounts (ignoring any report begin date). 
+It assumes that these accounts are under a top-level `asset` or `liability`
+account (plural forms also  allowed).
+          |],
          bvtitle    = "Balance Sheet",
          bvqueries  = [ ("Assets"     , journalAssetAccountQuery),
                         ("Liabilities", journalLiabilityAccountQuery)

hledger/Hledger/Cli/Cashflow.hs

@@ -14,6 +14,7 @@ module Hledger.Cli.Cashflow (
  ,tests_Hledger_Cli_Cashflow
 ) where
 
+import Data.String.Here
 import System.Console.CmdArgs.Explicit
 import Test.HUnit
 
@@ -24,7 +25,11 @@ import Hledger.Cli.BalanceView
 cfBV = BalanceView {
          bvmode     = "cashflow",
          bvaliases  = ["cf"],
-         bvhelp     = "show a cashflow statement",
+         bvhelp     = [here|This command displays a simple cashflow statement, showing changes
+in "cash" accounts. It assumes that these accounts are under a top-level 
+`asset` account and do not contain `receivable` or `A/R` in their name 
+(plural forms also allowed). 
+          |],
          bvtitle    = "Cashflow Statement",
          bvqueries  = [("Cash flows", journalCashAccountQuery)],
          bvtype     = PeriodChange

hledger/Hledger/Cli/Incomestatement.hs

@@ -11,6 +11,7 @@ module Hledger.Cli.Incomestatement (
  ,tests_Hledger_Cli_Incomestatement
 ) where
 
+import Data.String.Here
 import System.Console.CmdArgs.Explicit
 import Test.HUnit
 
@@ -21,7 +22,12 @@ import Hledger.Cli.BalanceView
 isBV = BalanceView {
          bvmode     = "incomestatement",
          bvaliases  = ["is"],
-         bvhelp     = "show an income statement",
+         bvhelp     = [here|This command displays a simple income statement, showing revenues
+and expenses during a period. It assumes that these accounts are under a 
+top-level `revenue` or `income` or `expense` account (plural forms 
+also allowed).
+
+          |],
          bvtitle    = "Income Statement",
          bvqueries  = [ ("Revenues", journalIncomeAccountQuery),
                         ("Expenses", journalExpenseAccountQuery)