doc: Scrubbed ALL sensor library descriptions

In an effort to clean-up and standardize UPM library
documentation, this commit updates (and in most cases,
unifies) the CMake description string AND CXX header
@comname string.

Strings were taken from datasheets when possible, spelling
mistakes were addressed, copy/paste errors where fixed,
Title Case was used, etc.

    * Tested/updated/added @web tags
    * Added/updated invalid sensor images
    * Added/updated @man tags, added missing manufacturers

Signed-off-by: Noel Eck <noel.eck@intel.com>

src/max31723/CMakeLists.txt

@@ -1,5 +1,5 @@
 set (libname "max31723")
-set (libdescription "Very accurate temperature sensor")
+set (libdescription "SPI/3-wire Digital Thermometer")
 set (module_src ${libname}.cxx)
 set (module_hpp ${libname}.hpp)
 upm_module_init(mraa)

src/max31723/max31723.hpp

@@ -43,10 +43,11 @@ namespace upm {
 /**
  * @library max31723
  * @sensor max31723
- * @comname MAX31723 Temperature Sensor
+ * @comname SPI/3-wire Digital Thermometer
  * @type temp
  * @man maxim
  * @con spi
+ * @web https://www.maximintegrated.com/en/products/analog/sensors-and-sensor-interface/MAX31723.html
  *
  * @brief API for the MAX31723 Temperature Sensor
  *