Make the rewrite rules copyable from the file, not just the render

The rules were a Markdown table, and a table cell cannot hold a bare `|`. It
has to be written `\|`, which renders as a pipe and copies as a backslash and
a pipe. Every one of these rules is an alternation full of pipes, so anyone
reading README.md rather than a rendered view -- which, for a self-hosted
thing, is most of the time -- got a regex whose alternation had quietly become
literal characters. It matches nothing, and nothing about it looks wrong.

That is not hypothetical: it is how this came up. The Reddit rule is the
longest row, and reading it out of the file gave something that plainly did
not work, so the backslashes came out. Which fixed the copy and broke the
table -- four pipes turned into column separators, the row became seven cells,
the separator row was widened to seven to match, and `(.*)` picked up an
escape on the way past.

Restoring the row would have left the trap exactly where it was, for the next
person or the same one. So the table is now a code block: each rule is a
comment naming the platform, then the find field, then the replace field, one
per line. Nothing is escaped, the file and the render agree, and each field is
a whole line to select.

Every rule is checked by reading the block out of README.md byte for byte with
no unescaping step -- the copy-paste path -- compiling it, and running it: all
seven, against nineteen URLs including mobile.x.com, threads.net, the TikTok
vm. and vt. hosts, five Reddit subdomains, a /s/ share link and a redd.it
short code.

Also reformats the rest of the file, and stops calling it a table on the way
past.

Co-Authored-By: Claude Opus 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_017nMQ2eDKnqALYhAibpTKTu

README.md

@@ -21,15 +21,43 @@ readable in your history.
 
 Replace `antisocial.example.com` with wherever you are running it.
 
-| Platform  | Find                                                          | Replace                                     |
-| --------- | ------------------------------------------------------------- | ------------------------------------------- |
-| X         | `/^https:\/\/(?:www\.\|mobile\.)?(?:x\|twitter)\.com\/(.*)$/` | `https://antisocial.example.com/x/$1`       |
-| Threads   | `/^https:\/\/(?:www\.)?threads\.(?:net\|com)\/(.*)$/`         | `https://antisocial.example.com/threads/$1` |
-| Instagram | `/^https:\/\/(?:www\.)?instagram\.com\/(.*)$/`                | `https://antisocial.example.com/ig/$1`      |
-| TikTok    | `/^https:\/\/(?:www\.\|vm\.\|vt\.)?tiktok\.com\/(.*)$/`       | `https://antisocial.example.com/tiktok/$1`  |
-| Bluesky   | `/^https:\/\/bsky\.app\/(.*)$/`                               | `https://antisocial.example.com/bsky/$1`    |
-| Reddit    | `/^https:\/\/(?:www\.\|old\.\|new\.\|np\.\|m\.)?reddit\.com\/(.*)$/` | `https://antisocial.example.com/reddit/$1` |
-| Reddit    | `/^https:\/\/redd\.it\/(.*)$/`                                | `https://antisocial.example.com/reddit/$1`  |
+Each rule is two fields. Both are on their own line below, and neither needs any
+escaping — copy them straight out of this file.
+
+```text
+# X
+/^https:\/\/(?:www\.|mobile\.)?(?:x|twitter)\.com\/(.*)$/
+https://antisocial.example.com/x/$1
+
+# Threads
+/^https:\/\/(?:www\.)?threads\.(?:net|com)\/(.*)$/
+https://antisocial.example.com/threads/$1
+
+# Instagram
+/^https:\/\/(?:www\.)?instagram\.com\/(.*)$/
+https://antisocial.example.com/ig/$1
+
+# TikTok
+/^https:\/\/(?:www\.|vm\.|vt\.)?tiktok\.com\/(.*)$/
+https://antisocial.example.com/tiktok/$1
+
+# Bluesky
+/^https:\/\/bsky\.app\/(.*)$/
+https://antisocial.example.com/bsky/$1
+
+# Reddit
+/^https:\/\/(?:www\.|old\.|new\.|np\.|m\.)?reddit\.com\/(.*)$/
+https://antisocial.example.com/reddit/$1
+
+# Reddit short links
+/^https:\/\/redd\.it\/(.*)$/
+https://antisocial.example.com/reddit/$1
+```
+
+A code block rather than a table, because a table cell cannot hold a bare `|` — it has
+to be written `\|`, which renders correctly and copies wrongly. The alternation in these
+rules is full of them, and a regex whose pipes arrive as literal pipes matches nothing
+and says nothing about why.
 
 So `https://x.com/user/status/123` becomes
 `https://antisocial.example.com/x/user/status/123`.
@@ -42,7 +70,8 @@ where it came from Reddit. A Reddit `/r/<sub>/s/<code>` share link is followed t
 post it points at, and that permalink — not the opaque share code — is what the copy
 button hands back.
 
-`/` serves this table with the live hostnames, if you'd rather read it there.
+`/` serves these rules with the live hostname already filled in, if you'd rather copy
+them from there.
 
 ## How it works