doc: fix typo 'BankAccount'

zhongsp · zhongsp · commit 7ee698c450e8 · 2015-03-26T11:29:56.000+08:00
diff --git a/doc/spec.md b/doc/spec.md
@@ -545,7 +545,7 @@ class CheckingAccount extends BankAccount {
 }
 ```
 
-In this example, the class 'CheckingAccount' *derives* from class 'BankAccount'. The constructor for 'CheckingAccount' calls the constructor for class 'BankAccount' using the 'super' keyword. In the emitted JavaScript code, the prototype of 'CheckingAccount' will chain to the prototype of 'BankingAccount'. 
+In this example, the class 'CheckingAccount' *derives* from class 'BankAccount'. The constructor for 'CheckingAccount' calls the constructor for class 'BankAccount' using the 'super' keyword. In the emitted JavaScript code, the prototype of 'CheckingAccount' will chain to the prototype of 'BankAccount'. 
 
 TypeScript classes may also specify static members. Static class members become properties of the class constructor. 
 

Original file line number	Diff line number	Diff line change
`@@ -545,7 +545,7 @@ class CheckingAccount extends BankAccount {`
`545`	`545`	`}`
`546`	`546`	```
`547`	`547`
`548`		`-In this example, the class 'CheckingAccount' derives from class 'BankAccount'. The constructor for 'CheckingAccount' calls the constructor for class 'BankAccount' using the 'super' keyword. In the emitted JavaScript code, the prototype of 'CheckingAccount' will chain to the prototype of 'BankingAccount'.`
	`548`	`+In this example, the class 'CheckingAccount' derives from class 'BankAccount'. The constructor for 'CheckingAccount' calls the constructor for class 'BankAccount' using the 'super' keyword. In the emitted JavaScript code, the prototype of 'CheckingAccount' will chain to the prototype of 'BankAccount'.`
`549`	`549`
`550`	`550`	`TypeScript classes may also specify static members. Static class members become properties of the class constructor.`
`551`	`551`