Adding ChiselEnum Documentation Entry (#1795)

* Adding ChiselEnum Documentation Entry

Added documentation for the ChiselEnum type with verified examples

* Fixed some doc ambiguity and repeated emitVerilog calls

* Added ChiselStage and commented out package definition since packages cannot be declared in single files

* Fixed issue with ChiselStage not being able to generate a module with parameters and bad package imports

* Opps on not adding _ after import

* Update docs/src/explanations/chisel-enum.md

Co-authored-by: Megan Wachs <megan@sifive.com>

* Update docs/src/explanations/chisel-enum.md

Co-authored-by: Megan Wachs <megan@sifive.com>

* Modified Bundle for ci and made changes to select naming scheme

* Update docs/src/explanations/chisel-enum.md

Co-authored-by: Megan Wachs <megan@sifive.com>

* Update docs/src/explanations/chisel-enum.md

Co-authored-by: Megan Wachs <megan@sifive.com>

* Update docs/src/explanations/chisel-enum.md

Co-authored-by: Megan Wachs <megan@sifive.com>

* Update docs/src/explanations/chisel-enum.md

Co-authored-by: Megan Wachs <megan@sifive.com>

* Added missing backticks

* Added space around error block quote

* Fixed md paragraph in code

* Update docs/src/explanations/chisel-enum.md

Co-authored-by: Megan Wachs <megan@sifive.com>

* Update docs/src/explanations/chisel-enum.md

Co-authored-by: Schuyler Eldridge <schuyler.eldridge@gmail.com>

* Update docs/src/explanations/chisel-enum.md

Co-authored-by: Schuyler Eldridge <schuyler.eldridge@gmail.com>

* Update docs/src/explanations/chisel-enum.md

Co-authored-by: Schuyler Eldridge <schuyler.eldridge@gmail.com>

* Update docs/src/explanations/chisel-enum.md

Co-authored-by: Megan Wachs <megan@sifive.com>

* Fixed some comments and formatting

Co-authored-by: Megan Wachs <megan@sifive.com>
Co-authored-by: Schuyler Eldridge <schuyler.eldridge@gmail.com>