Add some urls to boards.txt

While reviewing some of these boards, it was not immediately clear to me
what boards they referred to (especially with the relatively unbranded
boards from aliexpress). Just in case this helps anyone else, this adds
some urls with more info on those boards I found from the git history
and github issues.

Author: matthijskooijman

boards.txt

@@ -1210,6 +1210,7 @@ GenF4.build.series=STM32F4xx
 GenF4.build.cmsis_lib_gcc=arm_cortexM4lf_math
 
 # Black F407VE
+# https://github.com/mcauser/BLACK_F407VEZ
 GenF4.menu.pnum.BLACK_F407VE=Black F407VE
 GenF4.menu.pnum.BLACK_F407VE.upload.maximum_size=524288
 GenF4.menu.pnum.BLACK_F407VE.upload.maximum_data_size=131072
@@ -1218,6 +1219,7 @@ GenF4.menu.pnum.BLACK_F407VE.build.product_line=STM32F407xx
 GenF4.menu.pnum.BLACK_F407VE.build.variant=BLACK_F407XX
 
 # Black F407VG
+# https://github.com/mcauser/BLACK_F407VEZ with bigger chip
 GenF4.menu.pnum.BLACK_F407VG=Black F407VG
 GenF4.menu.pnum.BLACK_F407VG.upload.maximum_size=1048576
 GenF4.menu.pnum.BLACK_F407VG.upload.maximum_data_size=131072
@@ -1226,6 +1228,7 @@ GenF4.menu.pnum.BLACK_F407VG.build.product_line=STM32F407xx
 GenF4.menu.pnum.BLACK_F407VG.build.variant=BLACK_F407XX
 
 # Black F407ZE
+# https://github.com/mcauser/BLACK_F407ZE
 GenF4.menu.pnum.BLACK_F407ZE=Black F407ZE
 GenF4.menu.pnum.BLACK_F407ZE.upload.maximum_size=524288
 GenF4.menu.pnum.BLACK_F407ZE.upload.maximum_data_size=131072
@@ -1234,6 +1237,7 @@ GenF4.menu.pnum.BLACK_F407ZE.build.product_line=STM32F407xx
 GenF4.menu.pnum.BLACK_F407ZE.build.variant=BLACK_F407XX
 
 # Black F407ZG
+# https://github.com/mcauser/BLACK_F407ZG
 GenF4.menu.pnum.BLACK_F407ZG=Black F407ZG
 GenF4.menu.pnum.BLACK_F407ZG.upload.maximum_size=1048576
 GenF4.menu.pnum.BLACK_F407ZG.upload.maximum_data_size=131072
@@ -1274,6 +1278,7 @@ GenF4.menu.pnum.BLACKPILL_F401CC.build.product_line=STM32F401xC
 GenF4.menu.pnum.BLACKPILL_F401CC.build.variant=Generic_F401Cx
 
 # BlackPill F411CE
+# https://github.com/mcauser/WEACT_F411CEU6
 GenF4.menu.pnum.BLACKPILL_F411CE=BlackPill F411CE
 GenF4.menu.pnum.BLACKPILL_F411CE.upload.maximum_size=524288
 GenF4.menu.pnum.BLACKPILL_F411CE.upload.maximum_data_size=131072
@@ -1282,6 +1287,7 @@ GenF4.menu.pnum.BLACKPILL_F411CE.build.product_line=STM32F411xE
 GenF4.menu.pnum.BLACKPILL_F411CE.build.variant=Generic_F411Cx
 
 # Core board F401RCT6
+# https://stm32-base.org/boards/STM32F401RCT6-STM32F-Core-Board
 GenF4.menu.pnum.CoreBoard_F401RC=Core board F401RCT6
 GenF4.menu.pnum.CoreBoard_F401RC.upload.maximum_size=262144
 GenF4.menu.pnum.CoreBoard_F401RC.upload.maximum_data_size=65536
@@ -1298,6 +1304,7 @@ GenF4.menu.pnum.FEATHER_F405.build.product_line=STM32F405xx
 GenF4.menu.pnum.FEATHER_F405.build.variant=FEATHER_F405
 
 # ThunderPack F411xxE
+# https://github.com/jgillick/ThunderPack/tree/STM32F4
 GenF4.menu.pnum.THUNDERPACK_F411=ThunderPack v1.1+
 GenF4.menu.pnum.THUNDERPACK_F411.upload.maximum_size=524288
 GenF4.menu.pnum.THUNDERPACK_F411.upload.maximum_data_size=131072