Document file system path and directory entry limits

Author: jasnell

src/content/docs/workers/runtime-apis/nodejs/fs.mdx

@@ -76,6 +76,21 @@ Since all temporary files are held in memory, the total size of all temporary
 files created count towards your Worker’s memory limit. If you exceed this
 limit, the Worker instance will be terminated and restarted.
 
+The file system implementation has the following limits:
+
+* The maximum total length of a file path is 4096 characters, including path
+  separators. Because paths are handled as file URLs internally, the limit
+	accounts for percent-encoding of special characters, decoding characters
+	that do not need encoding before the limit is checked. For example, the
+	path `/tmp/abcde%66/ghi%zz' is 18 characters long because the `%66` does
+	not need to be percent-encoded and is therefore counted as one character,
+	while the `%zz` is an invalid percent-encoding that is counted as 3 characters.
+* The maximum number of path segments is 48. For example, the path `/a/b/c` is
+  3 segments.
+* The maxumum number of entries in a directory is 1024. This includes files,
+  directories, and symlinks.
+* The maximum size of an individual file is 128 MB total.
+
 :::
 
 The full `node:fs` API is documented in the [Node.js documentation for `node:fs`](https://nodejs.org/api/fs.html).