imp: bal: html output will use a hledger.css file, like bs/cf/is

hledger-lib/Hledger/Write/Html/Lucid.hs

@@ -25,6 +25,7 @@ type Html = Html.Html ()
 
 printHtml :: (Lines border) => [[Cell border Html]] -> Html
 printHtml table = do
+    Html.link_ [Html.rel_ "stylesheet", Html.href_ "hledger.css"]
     Html.style_ Attr.tableStylesheet
     Html.table_ $ traverse_ formatRow table
 

hledger/Hledger/Cli/Commands/Balance.hs

@@ -821,6 +821,7 @@ multiBalanceReportAsHtml ropts mbr =
   let
     (headingsrow,bodyrows,mtotalsrows) = multiBalanceReportHtmlRows ropts mbr
   in do
+    link_ [rel_ "stylesheet", href_ "hledger.css"]
     style_ tableStylesheet
     table_ $ mconcat $
          [headingsrow]