fix:print: remove unused --show-costs flag from command line help

hledger/Hledger/Cli/Commands/Print.hs

@@ -50,8 +50,6 @@ printmode = hledgerCommandMode
   $(embedFileRelative "Hledger/Cli/Commands/Print.txt")
   ([flagNone ["explicit","x"] (setboolopt "explicit")
     "show all amounts explicitly"
-  ,flagNone ["show-costs"] (setboolopt "show-costs")
-    "show transaction prices even with conversion postings"
   ,roundFlag
   ,flagNone ["invert"] (setboolopt "invert") "display all amounts with reversed sign"
   ,flagNone ["new"] (setboolopt "new")
@@ -159,8 +157,7 @@ printEntries opts@CliOpts{rawopts_=rawopts, reportspec_=rspec} j =
           -- Use the fully inferred and amount-styled/rounded transaction in the following situations:
           -- with -x/--explicit:
           | boolopt "explicit" (rawopts_ opts) = id
-          -- with --show-costs:
-          -- XXX infer_costs is --infer-costs not --show-costs. And where is show-costs used anyway ?
+          -- with --infer-costs
           | opts ^. infer_costs = id
           -- with -B/-V/-X/--value ("because of #551, and because of print -V valuing only one posting when there's an implicit txn price.")
           | has (value . _Just) opts = id

hledger/Hledger/Cli/Commands/Setup.hs

@@ -220,7 +220,7 @@ setupHledger = do
 
         -- pdesc "common general options are configured ?"
         -- --infer-costs"
-        -- print --explicit --show-costs"
+        -- print --explicit --infer-costs"
 
         return $ Just $ Right conf
   else

hledger/hledger.m4.md

@@ -578,7 +578,7 @@ in a more featureful hledger config file. Here's a small example:
 
 # Options following a `[COMMAND]` heading are used with that hledger command only.
 [print]
---explicit --show-costs
+--explicit --infer-costs
 ```
 
 To use a config file, specify it with the `--conf` option.

hledger/test/journal/costs.test

@@ -467,7 +467,7 @@ $ hledger -f- print --infer-costs
     assets                              $-135
     assets                               £-80
 
-$ hledger -f- print --show-costs --infer-costs
+$ hledger -f- print --infer-costs
 2011-01-01
     expenses:food                 €110 @@ £80
     expenses:foreign currency    €100 @@ $135