Support ~~~ syntax in md

Co-authored-by: Jakob Voss <voss@gbv.de>

docs/markdown.md

@@ -1,7 +1,7 @@
 # Markdown Scripts
 
 It's possible to write scripts using markdown. Only code blocks will be executed
-by zx. 
+by zx.
 
 > You can run this markdown file:
 >
@@ -14,6 +14,21 @@ await $`whoami`
 await $`echo ${__dirname}`
 ```
 
+~~~js
+await $`whoami`
+await $`echo ${__dirname}`
+~~~
+
+````js
+await $`whoami`
+await $`echo ${__dirname}`
+````
+
+~~~~js
+await $`whoami`
+await $`echo ${__dirname}`
+~~~~
+
 The `__filename` will be pointed to **markdown.md**:
 
 ```js
@@ -33,10 +48,44 @@ VAR=$(date)
 echo "$VAR" | wc -c
 ```
 
+~~~bash
+VAR=$(date)
+echo "$VAR" | wc -c
+~~~
+
+````bash
+VAR=$(date)
+echo "$VAR" | wc -c
+````
+
+~~~~bash
+VAR=$(date)
+echo "$VAR" | wc -c
+~~~~
+
 Other code blocks are ignored:
 
 ```css
 body .hero {
     margin: 42px;
 }
 ```
+
+~~~css
+body .hero {
+    margin: 42px;
+}
+~~~
+
+````css
+body .hero {
+    margin: 42px;
+}
+````
+
+~~~~css
+body .hero {
+    margin: 42px;
+}
+~~~~
+

src/cli.ts

@@ -187,22 +187,27 @@ function transformMarkdown(buf: Buffer) {
   const source = buf.toString()
   const output = []
   let state = 'root'
+  let sequence = ''
+  let match = ''
   let prevLineIsEmpty = true
   for (let line of source.split('\n')) {
     switch (state) {
       case 'root':
         if (/^( {4}|\t)/.test(line) && prevLineIsEmpty) {
           output.push(line)
           state = 'tab'
-        } else if (/^```(js|javascript)$/.test(line)) {
+        } else if (/^(```+|~~~+)(js|javascript)$/.test(line)) {
           output.push('')
           state = 'js'
-        } else if (/^```(sh|bash)$/.test(line)) {
+          sequence = line.match(/^(```+|~~~+)(js|javascript)$/)![1]
+        } else if (/^(```+|~~~+)(sh|bash)$/.test(line)) {
           output.push('await $`')
           state = 'bash'
-        } else if (/^```.*$/.test(line)) {
+          sequence = line.match(/^(```+|~~~+)(sh|bash)$/)![1]
+        } else if (/^(```+|~~~+).*$/.test(line)) {
           output.push('')
           state = 'other'
+          sequence = line.match(/^(```+|~~~+)(.*)$/)![1]
         } else {
           prevLineIsEmpty = line === ''
           output.push('// ' + line)
@@ -219,23 +224,23 @@ function transformMarkdown(buf: Buffer) {
         }
         break
       case 'js':
-        if (/^```$/.test(line)) {
+        if (line === sequence) {
           output.push('')
           state = 'root'
         } else {
           output.push(line)
         }
         break
       case 'bash':
-        if (/^```$/.test(line)) {
+        if (line === sequence) {
           output.push('`')
           state = 'root'
         } else {
           output.push(line)
         }
         break
       case 'other':
-        if (/^```$/.test(line)) {
+        if (line === sequence) {
           output.push('')
           state = 'root'
         } else {