Roff reader: handle \ line continuation in table cells.

Closes #11635.

src/Text/Pandoc/Readers/Roff.hs

@@ -268,7 +268,8 @@ tableCell = do
     manyTill anyChar (try (string "T}"))
   simpleCell = do
     tabChar <- tableTabChar <$> getState
-    many (notFollowedBy (char tabChar <|> newline) >> anyChar)
+    many $ (char '\\' >> anyChar)
+       <|> (notFollowedBy (char tabChar <|> newline) >> anyChar)
 
 tableRow :: PandocMonad m => RoffLexer m [RoffTokens]
 tableRow = do

test/command/11635.md

@@ -0,0 +1,28 @@
+```
+% pandoc -f man -t html
+.TH "TEST" "1" "2026-05-08"  "test v1.0.0" "test manual"
+.SH HEADING
+.TS
+tab(;);
+l l.
+this is a table element \
+written in two lines;abcdefg
+another \
+one;123456
+.TE
+^D
+<h1>HEADING</h1>
+<table>
+<tbody>
+<tr>
+<td style="text-align: left;">this is a table element written in two
+lines</td>
+<td style="text-align: left;">abcdefg</td>
+</tr>
+<tr>
+<td style="text-align: left;">another one</td>
+<td style="text-align: left;">123456</td>
+</tr>
+</tbody>
+</table>
+```