avrdude documentation improvement

[mcuee]

https://avrdudes.github.io/avrdude/7.3/avrdude.html

Some of the information are a bit outdated.

1. Windows installation -- maybe we want to point to the Wiki. We do not really recommend using Cygwin. We do not really support MinGW.org now (website down) but rather MSYS2 mingw project.
   https://avrdudes.github.io/avrdude/7.3/avrdude_34.html#Windows-Installation

2. Windows Configuration File Location -- I guess we can forget about 16bit Windows NT now. avrdude only works under Windows 7 and later.
   https://avrdudes.github.io/avrdude/7.3/avrdude_37.html#Windows-Configuration-File-Location

3. Windows port name -- no more parallel port support.
   https://avrdudes.github.io/avrdude/7.3/avrdude_39.html#Serial-Ports --> not so sure we want to mention libserialport improvement (only for MinGW build).
   https://avrdudes.github.io/avrdude/7.3/avrdude_40.html#Parallel-Ports

4. We need to remove Windows Parallel Port info here as well.
   https://avrdudes.github.io/avrdude/7.3/avrdude_4.html#Option-Descriptions

[mcuee]

Status: Done. PR #1689 merged.

---

I think some of the info below about serialupdi needs updates as well.
https://avrdudes.github.io/avrdude/7.3/avrdude_21.html#SerialUPDI-Programmer

@dbuchwald
Would you be able to help here? Thanks.

[mcuee]

• Documentation current avrdude limitations in pdf/html documentation #1672

More documentation update

• avrdude 7.3 release discussion #1473 (comment)

From @stefanrueger

I still think it would be wonderful if we had a short section in the .pdf/.html documentation about (current) limitations.

I have documented the knows limitations here and I just did some updates to list down the issues I know of.
https://github.com/avrdudes/avrdude/wiki/Known-limitations-of-avrdude

FAQ page may need some updates.
https://github.com/avrdudes/avrdude/wiki/FAQ

[dbuchwald]

Sorry, took me a while, but you can find updates to SerialUPDI documentation in PR #1689

[mcuee]

Sorry, took me a while, but you can find updates to SerialUPDI documentation in PR #1689

You are very fast already. Thanks.
PR #1689 looks good to me.

• Updated section about NVM models support #1689

[mcuee]

I think some of the info below about serialupdi needs updates as well. https://avrdudes.github.io/avrdude/7.3/avrdude_21.html#SerialUPDI-Programmer

@dbuchwald Would you be able to help here? Thanks.

Done. PR #1689 has been merged.