patch 8.2.2523: Svelte filetype not recognized

Problem:    Svelte filetype not recognized.
Solution:   Add a detection rule. (Brian Ryall, closes #7858)

runtime/filetype.vim

@@ -1491,6 +1491,9 @@ au BufNewFile,BufRead *.sdl,*.pr		setf sdl
 " sed
 au BufNewFile,BufRead *.sed			setf sed
 
+" svelte
+au BufNewFile,BufRead *.svelte			setf svelte
+
 " Sieve (RFC 3028, 5228)
 au BufNewFile,BufRead *.siv,*.sieve		setf sieve
 

src/testdir/test_filetype.vim

@@ -427,6 +427,7 @@ let s:filename_checks = {
     \ 'sdc': ['file.sdc'],
     \ 'sdl': ['file.sdl', 'file.pr'],
     \ 'sed': ['file.sed'],
+    \ 'svelte': ['file.svelte'],
     \ 'sensors': ['/etc/sensors.conf', '/etc/sensors3.conf', 'any/etc/sensors.conf', 'any/etc/sensors3.conf'],
     \ 'services': ['/etc/services', 'any/etc/services'],
     \ 'setserial': ['/etc/serial.conf', 'any/etc/serial.conf'],

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2523,
 /**/
     2522,
 /**/