Ports/mrsh: Fix workdir, remove or upgrade patches

Also removes mrsh from the list of ports missing descriptions. I tried
to be descriptive about the patches, but as I picked this port up from
someone else, I'm not 100% sure how to best explain the patches.

Ports/mrsh/patches/0003-Workaround-for-redundant-redeclaration-of-environ.patch

@@ -0,0 +1,26 @@
+From fa1d2ddff869430ad17e78755a06475307c49a7f Mon Sep 17 00:00:00 2001
+From: EWouters <6179932+EWouters@users.noreply.github.com>
+Date: Tue, 12 Apr 2022 18:01:44 +0200
+Subject: [PATCH 3/4] Workaround for redundant redeclaration of 'environ'
+
+---
+ main.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/main.c b/main.c
+index 0f433d2..577afde 100644
+--- a/main.c
++++ b/main.c
+@@ -14,7 +14,9 @@
+ #include <unistd.h>
+ #include "frontend.h"
+ 
++#ifndef __serenity__
+ extern char **environ;
++#endif
+ 
+ int main(int argc, char *argv[]) {
+ 	struct mrsh_state *state = mrsh_state_create();
+-- 
+2.32.0 (Apple Git-132)
+