Merge pull request #60 from tsingbx/assign

add doc for assign

105-Assignments/assign-1.gop

@@ -0,0 +1,10 @@
+# assignment
+// = is used for assigning.  The values of multiple variables can be changed in one line. In this way, their values can be swapped without an intermediary variable.
+var age int
+
+age = 21 // = is used for assigning.
+println age
+
+var a, b int = 0, 1
+a, b = b, a  // The values of multiple variables can be changed in one line.
+println a, b // 1, 0

105-Assignments/assign-2.gop

@@ -0,0 +1,8 @@
+# = vs :=
+// := is used for declaring and initializing. Multiple variables can be declared and intialized at one line.
+age := 21 // age is declared and initialized to 21
+println age
+
+a, b := 0, 1 // multiple variables can be declared and intialized at one line.
+a, b = b, a
+println a, b // 1, 0