git-check-attr: add page (#5098)

pages/common/git-check-attr.md

@@ -0,0 +1,20 @@
+# git check-attr
+
+> For every pathname, list if each attribute is unspecified, set, or unset as a gitattribute on that pathname.
+> More information: <https://git-scm.com/docs/git-check-attr>.
+
+- Check the values of all attributes on a file:
+
+`git check-attr --all {{path/to/file}}`
+
+- Check the value of a specific attribute on a file:
+
+`git check-attr {{attribute}} {{path/to/file}}`
+
+- Check the value of a specific attribute on files:
+
+`git check-attr --all {{path/to/file1}} {{path/to/file2}}`
+
+- Check the value of a specific attribute on one or more files:
+
+`git check-attr {{attribute}} {{path/to/file1}} {{path/to/file2}}`