[expect] correct documentation for stringMatching, not.stringMatching…

… to be in sync with Flow type (#5927)

* Correct doc for stringmatching, not stringmatching and some grammar mistakes

* Adjust doc according to PR review

* Correct the explanation again

docs/ExpectAPI.md

@@ -318,7 +318,7 @@ describe('not.objectContaining', () => {
 
 ### `expect.not.stringContaining(string)`
 
-`expect.not.stringContaining(string)` matches any received string that does not
+`expect.not.stringContaining(string)` matches the received string that does not
 contain the exact expected string.
 
 It is the inverse of `expect.stringContaining`.
@@ -333,9 +333,9 @@ describe('not.stringContaining', () => {
 });
 ```
 
-### `expect.not.stringMatching(regexp)`
+### `expect.not.stringMatching(string | regexp)`
 
-`expect.not.stringMatching(regexp)` matches any received string that does not
+`expect.not.stringMatching(string | regexp)` matches the received string that does not
 match the expected regexp.
 
 It is the inverse of `expect.stringMatching`.
@@ -379,12 +379,12 @@ test('onPress gets called with the right thing', () => {
 
 ### `expect.stringContaining(string)`
 
-`expect.stringContaining(string)` matches any received string that contains the
+`expect.stringContaining(string)` matches the received string that contains the
 exact expected string.
 
-### `expect.stringMatching(regexp)`
+### `expect.stringMatching(string | regexp)`
 
-`expect.stringMatching(regexp)` matches any received string that matches the
+`expect.stringMatching(string | regexp)` matches the received string that matches the
 expected regexp.
 
 You can use it instead of a literal value: