runtime(cs): Update C# runtime files

closes: #16884

Signed-off-by: Nick Jensen <nickspoon@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/syntax.txt b/runtime/doc/syntax.txt
index 8115371..a44b6f6 100644
--- a/runtime/doc/syntax.txt
+++ b/runtime/doc/syntax.txt
@@ -1,4 +1,4 @@
-*syntax.txt*	For Vim version 9.1.  Last change: 2025 Mar 10
+*syntax.txt*	For Vim version 9.1.  Last change: 2025 Mar 15
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -1286,6 +1286,21 @@
 startup vimrc: >
    :let filetype_w = "cweb"
 
+CSHARP							 *cs.vim* *ft-cs-syntax*
+
+C# raw string literals may use any number of quote marks to encapsulate the
+block, and raw interpolated string literals may use any number of braces to
+encapsulate the interpolation, e.g. >
+
+    $$$""""Hello {{{name}}}""""
+<
+By default, Vim highlights 3-8 quote marks, and 1-8 interpolation braces.
+The maximum numbers of quotes and braces recognized can configured using the
+following variables:
+
+    Variable					Default ~
+    g:cs_raw_string_quote_count			8
+    g:cs_raw_string_interpolation_brace_count	8
 
 DART						*dart.vim* *ft-dart-syntax*
 
diff --git a/runtime/doc/tags b/runtime/doc/tags
index 3bd49d9..c25effa 100644
--- a/runtime/doc/tags
+++ b/runtime/doc/tags
@@ -6722,6 +6722,7 @@
 credits	intro.txt	/*credits*
 crontab	options.txt	/*crontab*
 cs-find	if_cscop.txt	/*cs-find*
+cs.vim	syntax.txt	/*cs.vim*
 cs7-problem	term.txt	/*cs7-problem*
 cscope	if_cscop.txt	/*cscope*
 cscope-commands	if_cscop.txt	/*cscope-commands*
@@ -7319,6 +7320,7 @@
 ft-context-mappings	ft_context.txt	/*ft-context-mappings*
 ft-context-settings	ft_context.txt	/*ft-context-settings*
 ft-cpp-syntax	syntax.txt	/*ft-cpp-syntax*
+ft-cs-syntax	syntax.txt	/*ft-cs-syntax*
 ft-csh-syntax	syntax.txt	/*ft-csh-syntax*
 ft-css-omni	insert.txt	/*ft-css-omni*
 ft-csv-syntax	syntax.txt	/*ft-csv-syntax*