docs: Minor updates to wording of some documents

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

docs/Firmware_Commands.md

@@ -46,12 +46,12 @@ Common startup commands:
 * set_pwm_out pin=%u cycle_ticks=%u value=%c : This command will
   immediately configure the given pin to use hardware based
   pulse-width-modulation (PWM) with the given number of
-  cycle_ticks. The "cycle_ticks" is the amount of time (in MCU clock
+  cycle_ticks. The "cycle_ticks" is the number of MCU clock ticks each
-  ticks) in a complete power on and power off cycle. A cycle_ticks
+  power on and power off cycle should last. A cycle_ticks value of 1
-  value of 1 can be used to request the fastest possible cycle
+  can be used to request the fastest possible cycle time. The "value"
-  time. The specified "value" is between 0 and 255 with 0 indicating a
+  parameter is between 0 and 255 with 0 indicating a full off state
-  full off state and 255 indicating a full on state. This command may
+  and 255 indicating a full on state. This command may be useful for
-  be useful for enabling CPU and nozzle cooling fans.
+  enabling CPU and nozzle cooling fans.
 
 * send_spi_message pin=%u msg=%*s : This command can be used to
   transmit messages to a serial-peripheral-interface (SPI) component

docs/Installation.md

@@ -1,8 +1,7 @@
 Klipper is currently in an experimental state. These instructions
 assume the software will run on a Raspberry Pi computer in conjunction
-with OctoPrint. Klipper supports only Atmel ATmega based
+with OctoPrint. Klipper supports Atmel ATmega based micro-controllers
-micro-controllers and Arduino Due (Atmel SAM3x8e ARM
+and Arduino Due (Atmel SAM3x8e ARM micro-controllers) printers.
-micro-controllers) printers at this time.
 
 It is recommended that a Raspberry Pi 2 or Raspberry Pi 3 computer be
 used as the host. The software will run on a first generation

docs/Protocol.md

@@ -28,19 +28,19 @@ DECL_COMMAND(command_set_digital_out, "set_digital_out pin=%u value=%c");
 
 The above declares a command named "set_digital_out". This allows the
 host to "invoke" this command which would cause the
-command_set_digital_out() C function will be executed in the
+command_set_digital_out() C function to be executed in the
 firmware. The above also indicates that the command takes two integer
 parameters. When the command_set_digital_out() C code is executed, it
 will be passed an array containing these two integers - the first
 corresponding to the 'pin' and the second corresponding to the
 'value'.
 
-In general, the parameters are described with printf() style
+In general, the parameters are described with printf() style syntax
-parameters (eg, "%u"). In the above example, "value=" is a parameter
+(eg, "%u"). In the above example, "value=" is a parameter name and
-name and "%c" indicates the parameter is an integer. The parameter
+"%c" indicates the parameter is an integer. The parameter name is used
-name is used as documentation. In this example, the "%c" is used as
+as documentation. In this example, the "%c" is used as documentation
-documentation to indicate the expected integer is 1 byte in size (the
+to indicate the expected integer is 1 byte in size (the declared
-declared integer size does not impact the parsing or encoding).
+integer size does not impact the parsing or encoding).
 
 At firmware compile time, the build will collect all commands declared
 with DECL_COMMAND(), determine their parameters, and arrange for them