Update subtractassign.json

Signed-off-by: Arya Gupta <arya.gupta99999@gmail.com>

Author: Arya-Gupta

content/references/translations/en/processing/subtractassign.json

@@ -3,13 +3,13 @@
   "brief": "Combines subtraction with assignment",
   "description": "Combines subtraction with assignment. The expression <b>a -= b</b> is equivalent to <b>a = a - b</b>. \n",
   "related": ["addassign", "minus"],
-  "syntax": ["value1 -= value2"],
+  "syntax": ["var -= value"],
   "returns": "",
   "type": "function",
   "category": "math",
   "subcategory": "Operators",
   "parameters": [
-    { "name": "value1", "description": "int or float", "type": [] },
-    { "name": "value2", "description": "int or float", "type": [] }
+    { "name": "var", "description": "int or float", "type": [] },
+    { "name": "value", "description": "any numerical value the same datatype as var", "type": [] }
   ]
 }