Fix spelling typos in files under doc/esp8266wifi (#7520)

This patch fixes some spelling typos in following files
bearssl-client-secure-class.rst
client-class.rst
scan-class.rst
scan-examples.rst
server-examples.rst

doc/esp8266wifi/bearssl-client-secure-class.rst

@@ -139,7 +139,7 @@ setFingerprint(const uint8_t fp[20]) / setFingerprint(const char \*fpStr)
 
 Verify the SHA1 fingerprint of the certificate returned matches this one.  If the server certificate changes, it will fail.  If an array of 20 bytes are sent in, it is assumed they are the binary SHA1 values.  If a `char*` string is passed in, it is parsed as a series of human-readable hex values separated by spaces or colons (e.g. `setFingerprint("00:01:02:03:...:1f");`)
 
-This fingerprint is calcuated on the raw X509 certificate served by the server.  In very rare cases, these certificates have certain encodings which should be normalized before taking a fingerprint (but in order to preserve memory BearSSL does not do this normalization since it would need RAM for an entire copy of the cert), and the fingerprint BearSSL calculates will not match the fingerprint OpenSSL calculates.  In this case, you can enable SSL debugging and get a dump of BearSSL's calculated fingerprint and use that one in your code, or use full certificate validation.  See the `original issue and debug here <https://github.com/esp8266/Arduino/issues/6209>`__.
+This fingerprint is calculated on the raw X509 certificate served by the server.  In very rare cases, these certificates have certain encodings which should be normalized before taking a fingerprint (but in order to preserve memory BearSSL does not do this normalization since it would need RAM for an entire copy of the cert), and the fingerprint BearSSL calculates will not match the fingerprint OpenSSL calculates.  In this case, you can enable SSL debugging and get a dump of BearSSL's calculated fingerprint and use that one in your code, or use full certificate validation.  See the `original issue and debug here <https://github.com/esp8266/Arduino/issues/6209>`__.
 
 setTrustAnchors(BearSSL::X509List \*ta)
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

doc/esp8266wifi/client-class.rst

@@ -61,7 +61,7 @@ In this mode, every ``write()`` is flushed.  It means that after a call to
 
 When set to ``true`` in ``WiFiClient`` implementation,
 
-- It slows down transfers, and implicitely disable the Nagle algorithm.
+- It slows down transfers, and implicitly disable the Nagle algorithm.
 
 - It also allows to avoid a temporary copy of data that otherwise consumes
   at most ``TCP_SND_BUF`` = (2 * ``MSS``) bytes per connection,

doc/esp8266wifi/scan-class.rst

@@ -191,7 +191,7 @@ Return information if a network discovered during the scan is hidden or not.
 
     WiFi.isHidden(networkItem)
 
-Returned value if the ``bolean`` type, and ``true`` means that network is hidden. The ``networkItem`` is a zero based index of network discovered during scan.
+Returned value if the ``boolean`` type, and ``true`` means that network is hidden. The ``networkItem`` is a zero based index of network discovered during scan.
 
 getNetworkInfo
 ^^^^^^^^^^^^^^

doc/esp8266wifi/scan-examples.rst

@@ -206,7 +206,7 @@ Complete sketch is below. The code inside ``setup()`` is the same as described i
         lastScanMillis = currentMillis;
       }
 
-      // print out Wi-Fi network scan result uppon completion
+      // print out Wi-Fi network scan result upon completion
       int n = WiFi.scanComplete();
       if(n >= 0)
       {

doc/esp8266wifi/server-examples.rst

@@ -204,7 +204,7 @@ Complete sketch is presented below.
 
         // close the connection:
         client.stop();
-        Serial.println("[Client disonnected]");
+        Serial.println("[Client disconnected]");
       }
     }
 
@@ -236,7 +236,7 @@ The page would be refreshed every 5 seconds. Each time this happens, you should
     Host: 192.168.1.104
     DNT: 1
     Connection: Keep-Alive
-    [client disonnected]
+    [client disconnected]
 
 Conclusion
 ~~~~~~~~~~