Fixed module descriptions

Author: fzhinkin

core/Module.md

@@ -75,10 +75,10 @@ fun Message.Companion.fromBson(source: Source): Message {
 }
 ```
 
-# Package kotlinx.io
-
-Core IO primitives.
-
 #### Thread-safety guarantees
 
 Until stated otherwise, types and functions provided by the library are not thread safe.
+
+# Package kotlinx.io
+
+Core IO primitives.

filesystem/Module.md

@@ -2,10 +2,6 @@
 
 The module provides experimental files and filesystem support. The API is unstable and will change in the future.
 
-# Package kotlinx.io.files
-
-Basic API for working with files.
-
 #### Thread-safety guarantees
 
 Until stated otherwise, types and functions provided by the library are not thread safe.
@@ -14,6 +10,11 @@ Until stated otherwise, types and functions provided by the library are not thre
 
 [//]: <> (TODO: Link to SystemFileSystem doesn't work)
 - For JS and Wasm, [kotlinx.io.files.SystemFileSystem] is supported only in the NodeJs environment. Attempts to use it
-in the browser environment will result in a runtime error.
+  in the browser environment will result in a runtime error.
 - [#312](https://github.com/Kotlin/kotlinx-io/issues/312) For `wasmWasi` target, directory listing ([kotlinx.io.files.FileSystem.list]) does not work with NodeJS runtime on Windows,
-as `fd_readdir` function is [not implemented there](https://github.com/nodejs/node/blob/6f4d6011ea1b448cf21f5d363c44e4a4c56ca34c/deps/uvwasi/src/uvwasi.c#L19).
+  as `fd_readdir` function is [not implemented there](https://github.com/nodejs/node/blob/6f4d6011ea1b448cf21f5d363c44e4a4c56ca34c/deps/uvwasi/src/uvwasi.c#L19).
+
+# Package kotlinx.io.files
+
+Basic API for working with files.
+