[Docs] .skyignore doc (#4114)

* [Docs] .skyignore doc

* Correct typos

Co-authored-by: Zongheng Yang <[email protected]>

---------

Co-authored-by: Zongheng Yang <[email protected]>

docs/source/examples/syncing-code-artifacts.rst

@@ -46,31 +46,7 @@ VMs.  The task is invoked under that working directory (so that it can call
 scripts, access checkpoints, etc.).
 
 .. note::
-
-    **Exclude files from syncing**
-
-    For large, multi-gigabyte workdirs, uploading may be slow because they
-    are synced to the remote VM(s). To exclude large files in
-    your workdir from being uploaded, add them to a :code:`.skyignore` file 
-    under your workdir. :code:`.skyignore` follows RSYNC filter rules. 
-
-    Example :code:`.skyignore` file:
-
-    .. code-block::
-        
-      # Files that match pattern under ONLY CURRENT directory
-      /hello.py
-      /*.txt
-      /dir
-
-      # Files that match pattern under ALL directories
-      *.txt
-      hello.py
-
-      # Files that match pattern under a directory ./dir/
-      /dir/*.txt
-    
-    Do NOT use ``.`` to indicate local directory (e.g. ``./hello.py``).
+  To exclude large files from being uploaded, see :ref:`exclude-uploading-files`.
 
 .. note::
 
@@ -140,6 +116,33 @@ file_mount may be slow because they are processed by ``rsync``.  Use
 :ref:`SkyPilot bucket mounting <sky-storage>` to efficiently handle
 large files.
 
+.. _exclude-uploading-files:
+
+Exclude uploading files
+--------------------------------------
+By default, SkyPilot uses your existing :code:`.gitignore` and :code:`.git/info/exclude` to exclude files from syncing.
+
+Alternatively, you can use :code:`.skyignore` if you want to separate SkyPilot's syncing behavior from Git's.
+If you use a :code:`.skyignore` file, SkyPilot will only exclude files based on that file without using the default Git files.
+
+Any :code:`.skyignore` file under either your workdir or source paths of file_mounts is respected.
+
+:code:`.skyignore` follows RSYNC filter rules, e.g.
+
+.. code-block::
+
+  # Files that match pattern under CURRENT directory
+  /file.txt
+  /dir
+  /*.jar
+  /dir/*.jar
+
+  # Files that match pattern under ALL directories
+  *.jar
+  file.txt
+
+Do _not_ use ``.`` to indicate local directory (e.g., instead of ``./file``, write ``/file``).
+
 .. _downloading-files-and-artifacts:
 
 Downloading files and artifacts

docs/source/reference/yaml-spec.rst

@@ -22,8 +22,8 @@ Available fields:
     # If a relative path is used, it's evaluated relative to the location from 
     # which `sky` is called.
     #
-    # To exclude files from syncing, add them to a .skyignore file under your working directory.
-    # Details: https://skypilot.readthedocs.io/en/latest/examples/syncing-code-artifacts.html#uploading-code-and-project-files
+    # To exclude files from syncing, see 
+    # https://skypilot.readthedocs.io/en/latest/examples/syncing-code-artifacts.html#exclude-uploading-files
     workdir: ~/my-task-code
 
     # Number of nodes (optional; defaults to 1) to launch including the head node.