Add documentation for AlignAssignmentStatement rule

Author: Kapil Borle

RuleDocumentation/AlignAssignmentStatement.md

@@ -1,17 +1,48 @@
 # AlignAssignmentStatement
+
 **Severity Level: Warning**
 
 ## Description
 
-## How to Fix
+Consecutive assignment statements are more readable if they are aligned. By aligned, we imply that the `equal` sign for all the assignment statements should be in the same column.
 
-## Example
-### Wrong：
-```PowerShell
+The rule looks for key (property) value pairs in a hashtable (DSC configuration) to check if they are aligned or not. Consider the following example in which the key value pairs are not aligned.
 
+```powershell
+$hashtable = @{
+    property1 = "value"
+    anotherProperty = "another value"
+}
 ```
 
-### Correct:
-```PowerShell
+Alignment in this case would look like the following.
+
+```powershell
+$hashtable = @{
+    property1       = "value"
+    anotherProperty = "another value"
+}
+```
+
+The rule will ignore hashtables in which the assignment statements are on the same line. For example, the rule will ignore `$h = {a = 1; b = 2}`.
+
+## Configuration
 
+```powershell
+    Rules = @{
+        PSAlignAssignmentStatement = @{
+            Enable = $true
+            CheckHashtable = $true
+        }
+    }
 ```
+
+### Parameters
+
+#### Enable: bool (Default value is `$false`)
+
+Enable or disable the rule during ScriptAnalyzer invocation.
+
+#### CheckHashtable: bool (Default value is `$false`)
+
+Enforce alignment of assignment statements in a hashtable and in a DSC Configuration. There is only one switch for hasthable and DSC configuration because the property value pairs in a DSC configuration are parsed as key value pairs of a hashtable.