Filled in docstring for abs

Author: oleksandr-pavlyk

dpctl/tensor/_elementwise_funcs.py

@@ -20,7 +20,22 @@
 
 # U01: ==== ABS    (x)
 _abs_docstring_ = """
+abs(x, out=None, order='K')
+
 Calculate the absolute value element-wise.
+
+Args:
+    x (usm_ndarray):
+        Input array, expected to have numeric data type.
+    out (usm_ndarray):
+        Output array to populate. Array have the correct
+        shape and the expected data type.
+    order ("C","F","A","K", optional): memory layout of the newly
+        output array, if parameter `out` is `None`.
+        Default: "K".
+Return:
+    usm_ndarray:
+        An array containing the element-wise absolute values.
 """
 
 abs = UnaryElementwiseFunc("abs", ti._abs_result_type, ti._abs, _abs_docstring_)