Add SparkFun I2C Expander library

[nseidle]

No description provided.

[github-actions]

Arduino Lint has suggestions for possible improvements to https://github.com/sparkfun/SparkFun_I2C_Expander_Arduino_Library:

Linting library in SparkFun_I2C_Expander_Arduino_Library
WARNING: library.properties name value SparkFun I2C Expander Arduino Library is longer than the recommended length of 16
         characters.                                                                                                    
         See: https://arduino.github.io/arduino-cli/latest/library-specification/#libraryproperties-file-format         
         (Rule LP010)                                                                                                   
WARNING: Library name SparkFun I2C Expander Arduino Library contains "Arduino". This is superfluous.           
         See: https://arduino.github.io/arduino-cli/latest/library-specification/#libraryproperties-file-format
         (Rule LP014)                                                                                          
WARNING: library.properties name SparkFun I2C Expander Arduino Library contains spaces. Although supported, best        
         practices is to not use spaces.                                                                                
         See: https://arduino.github.io/arduino-cli/latest/library-specification/#libraryproperties-file-format         
         (Rule LP015)                                                                                                   
WARNING: Library name SparkFun I2C Expander Arduino Library contains "library". This is superfluous.           
         See: https://arduino.github.io/arduino-cli/latest/library-specification/#libraryproperties-file-format
         (Rule LP016)                                                                                          
WARNING: Unable to load the library.properties url field: 404 Not Found                                        
         See: https://arduino.github.io/arduino-cli/latest/library-specification/#libraryproperties-file-format
         (Rule LP042)                                                                                          

Linter results for project: 0 ERRORS, 5 WARNINGS

-------------------

Linting sketch in SparkFun_I2C_Expander_Arduino_Library/examples/Example1-DigitalOutput

Linter results for project: no errors or warnings

-------------------

Linting sketch in SparkFun_I2C_Expander_Arduino_Library/examples/Example2-Read

Linter results for project: no errors or warnings

-------------------

Linting sketch in SparkFun_I2C_Expander_Arduino_Library/examples/Example3-InterruptRead

Linter results for project: no errors or warnings

-------------------

Linter results for projects: 0 ERRORS, 5 WARNINGS

[github-actions]

Your submission has now been accepted! Thanks for your contribution to the Arduino Library Manager index.

The library(s) will be available for installation via Library Manager within a day's time.

You can check the logs from the Library Manager indexer for your library(s) here:
http://downloads.arduino.cc/libraries/logs/github.com/sparkfun/SparkFun_I2C_Expander_Arduino_Library/