Small grammar fixes and clarifications (espressif#1003)

* Small grammar fixes and clarifications Just fixed some small grammar issues in the comments and clarified a few things that might seem confusing. * More spelling fixes that I introduced...

Author: joeybab3

libraries/Preferences/examples/StartCounter/StartCounter.ino

@@ -1,8 +1,8 @@
 /*
- ESP32 start counter example with Preferences library
+ ESP32 startup counter example with Preferences library.
 
- This simple example demonstrate using Preferences library to store how many times
- was ESP32 module started. Preferences library is wrapper around Non-volatile
+ This simple example demonstrates using the Preferences library to store how many times
+ the ESP32 module has booted. The Preferences library is a wrapper around the Non-volatile
  storage on ESP32 processor.
 
  created for arduino-esp32 09 Feb 2017
@@ -17,29 +17,29 @@ void setup() {
  Serial.begin(115200);
  Serial.println();
 
- // Open Preferences with my-app namespace. Each application module, library, etc.
- // has to use namespace name to prevent key name collisions. We will open storage in
+ // Open Preferences with my-app namespace. Each application module, library, etc
+ // has to use a namespace name to prevent key name collisions. We will open storage in
  // RW-mode (second parameter has to be false).
- // Note: Namespace name is limited to 15 chars
+ // Note: Namespace name is limited to 15 chars.
  preferences.begin("my-app", false);
 
- // Remove all preferences under opened namespace
+ // Remove all preferences under the opened namespace
  //preferences.clear();
 
  // Or remove the counter key only
  //preferences.remove("counter");
 
- // Get a counter value, if key is not exist return default value 0
- // Note: Key name is limited to 15 chars too
+ // Get the counter value, if the key does not exist, return a default value of 0
+ // Note: Key name is limited to 15 chars.
  unsigned int counter = preferences.getUInt("counter", 0);
 
- // Increase counter
+ // Increase counter by 1
  counter++;
 
- // Print counter to a Serial
+ // Print the counter to Serial Monitor
  Serial.printf("Current counter value: %u\n", counter);
 
- // Store counter to the Preferences
+ // Store the counter to the Preferences
  preferences.putUInt("counter", counter);
 
  // Close the Preferences
@@ -53,4 +53,4 @@ void setup() {
  ESP.restart();
 }
 
-void loop() {}
+void loop() {}