new profiles for Xiaomi routers 3gv2/r4a/rb02/r4v2

Extended size for the "firmware" mtd partition, unused partitions were removed

Delete profiles/D-LINK/DIR-300_b5b6b7_8mb.config

one more profile for the Xiaomi MiWiFi mini

Extended firmware partition of spi flash for the Xiaomi MiWiFi mini.
Firmware partition has been increased due to another section - overlay (0x100000)

repair support of the mt7620

- support of the mt7620 was repaired
- new "Xiaomi mi mini" profile
- others profiles were updated

screenshots were updated

fix of the factory partition update

factory partition of the xiaomi mi router 4a gigabit (rgv2/r4ag/r4agv2/rb02)  is locate after the bdata partition

minors html updates