Update Flycast and ClownMDEmu docs. (#1084)

* Update Flycast information.

Flycast can fall-back on high-level BIOS emulation, so an official
BIOS is not required.

RetroAchievements appear to work just fine, as I was able to get all
achievements in Sonic Adventure without issue.

* ClownMDEmu now uses the subsystem API.

* Add ClownMDEmu's new widescreen option.

---------

Co-authored-by: Clownacy <[email protected]>

Author: Clownacy

docs/library/clownmdemu.md

@@ -51,7 +51,7 @@ Frontend-level settings or features that the ClownMDEmu core respects:
 | Sensors           | ✕         |
 | Camera            | ✕         |
 | Location          | ✕         |
-| Subsystem         | ✕         |
+| Subsystem         | ✔         |
 | [Softpatching](../guides/softpatching.md) | ✔         |
 | Disk Control      | ✕         |
 | Username          | ✕         |
@@ -84,7 +84,7 @@ The ClownMDEmu core saves/loads to/from these directories.
 - The ClownMDEmu core's core-provided sample rate is 223721.5625 Hz
 - The ClownMDEmu core's base width is 320 (though this varies depending on the loaded content)
 - The ClownMDEmu core's base height is 224 (though this varies depending on the loaded content)
-- The ClownMDEmu core's max width is 320
+- The ClownMDEmu core's max width is 400
 - The ClownMDEmu core's max height is 480
 - The ClownMDEmu core's core-provided aspect ratio is typically 10:7 (though this varies depending on the loaded content)
 
@@ -196,6 +196,10 @@ The ClownMDEmu core has the following option(s) that can be tweaked from the cor
 
 	Makes games that use Interlace Mode 2 for split-screen not appear squashed.
 
+- **Widescreen Hack** [clownmdemu_widescreen] (**disabled**|enabled)
+
+	Widens the display. Works well with some games, badly with others.
+
 - **Low-Pass Filter** [clownmdemu_lowpass_filter] (**enabled**|disabled)
 
 	Makes the audio sound 'softer', just like on a real Mega Drive.

docs/library/flycast.md

@@ -53,7 +53,7 @@ Required or optional firmware files go in RetroArch's system directory.
 
 |   Filename      |    Description                                                       |              md5sum              |
 |:---------------:|:--------------------------------------------------------------------:|:--------------------------------:|
-| dc/dc_boot.bin  | Dreamcast BIOS - Required for Dreamcast                              | e10c53c2f8b90bab96ead2d368858623 |
+| dc/dc_boot.bin  | Dreamcast BIOS - Optional                                            | e10c53c2f8b90bab96ead2d368858623 |
 | dc/naomi.zip    | NAOMI BIOS from MAME - Optional                                      |                                  |
 | dc/hod2bios.zip | NAOMI The House of the Dead 2 BIOS from MAME - Optional              |                                  |
 | dc/f355dlx.zip  | NAOMI Ferrari F355 Challenge (deluxe) BIOS from MAME - Optional      |                                  |
@@ -77,7 +77,7 @@ Required or optional firmware files go in RetroArch's system directory.
 | Rewind            | ✕         |
 | Netplay           | ✕         |
 | Core Options      | ✔         |
-| RetroAchievements | ✕         |
+| RetroAchievements | ✔         |
 | RetroArch Cheats  | ✔         |
 | Native Cheats     | ✕         |
 | Controls          | ✔         |