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/hx711/CMakeLists.txt

@@ -1,5 +1,5 @@
 set (libname "hx711")
-set (libdescription "HX711 24bit ADC")
+set (libdescription "24-bit Analog-to-digital Converter")
 set (module_src ${libname}.cxx)
 set (module_hpp ${libname}.hpp)
 upm_module_init(mraa)

src/hx711/hx711.hpp

@@ -37,7 +37,7 @@ namespace upm {
      /**
       * @library hx711
       * @sensor hx711
-      * @comname HX711 Analog-to-Digital Converter
+      * @comname 24-bit Analog-to-digital Converter
       * @type electric
       * @man generic
       * @web http://www.dfrobot.com/image/data/SEN0160/hx711_english.pdf