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/emg/CMakeLists.txt

@@ -1,5 +1,5 @@
 upm_mixed_module_init (NAME emg
-    DESCRIPTION "Electromyography (EMG) detector"
+    DESCRIPTION "Electromyography (EMG) Sensor"
     C_HDR emg.h
     C_SRC emg.c
     CPP_HDR emg.hpp

src/emg/emg.hpp

@@ -36,7 +36,7 @@ namespace upm {
   /**
    * @library emg
    * @sensor emg
-   * @comname EMG Sensor
+   * @comname Electromyography (EMG) Sensor
    * @altname Grove EMG Sensor
    * @type electric
    * @man seeed