add file.read_combined_object & update filesystem docs

doc/en/scripting/filesystem.md

@@ -2,78 +2,7 @@
 
 ### *file* library
 
-Filesystem interaction library.
-
-```python
-file.resolve(path: str) -> str
-```
-
-Function turns `entry_point:path` (example `user:worlds/house1`) to a regular path. (example `C://Users/user/.voxeng/worlds/house1`)
-
-> [!NOTE]
-> The function should be used for debug only. *entry_point:path* notation is required in all **file** functions.
-
-Resulting path is not canonical and may be relative.
-
-```python
-file.read(path: str) -> str
-```
-
-Read whole text file.
-
-```python
-file.read_bytes(path: str) -> array of integers
-```
-
-Read file into bytes array.
-
-```python
-file.write(path: str, text: str) -> nil
-```
-
-Overwrite text file.
-
-```python
-file.write_bytes(path: str, data: array of integers)
-```
-
-Overwrite binary file with bytes array.
-
-```python
-file.length(path: str) -> int
-```
-
-Get file length (bytes) or 0.
-
-```python
-file.exists(path: str) -> bool
-```
-
-Check if file or directory exist.
-
-```python
-file.isfile(path: str) -> bool
-```
-
-Check if the path points to a file.
-
-```python
-file.isdir(path: str) -> bool
-```
-
-Check if the path points to a directory.
-
-```python
-file.mkdir(path: str) -> bool
-```
-
-Create directory. Returns true if new directory created
-
-```python
-file.mkdirs(path: str) -> bool
-```
-
-Create directories chain. Returns true if new directory created.
+See [file library](builtins/libfile.md)
 
 ## *json* library