Update all code's readme

add pre-compiled uf2 link

Code/FUZIX/README.md

@@ -13,3 +13,6 @@ make world
 ```
 
 Copy `build/fuzix.uf2` into picocalc like every pico device 
+
+# Pre-compiled uf2
+https://github.com/clockworkpi/PicoCalc/blob/master/Bin/PicoCalc%20SD/firmware/PicoCalc_Fuzix_v1.0.uf2

Code/MP3Player/README.md

@@ -46,7 +46,7 @@ make
 Copy pico-mp3-player.uf2 to picocalc
 
 ### Notes
-Currently only supports up to 64 mp3s, only ascii characters are legal mp3 filename.
+Currently only supports up to **64** mp3 files, and only ascii characters are legal mp3 filename.
 
 #### Special thanks
 
@@ -55,4 +55,8 @@ https://git.fh-aachen.de/Terstegge/YAHAL
 Thanks to YAHAL  
 Without this great project YAHAL, mp3 playback on pico would be a pain  
 
+## Pre-compiled uf2
+
+https://github.com/clockworkpi/PicoCalc/blob/master/Bin/PicoCalc%20SD/firmware/PicoCalc_MP3Player_v0.5.uf2
+
 

Code/NES/README.md

@@ -24,5 +24,8 @@ press -(select) and =(start) together, will reset the emulator to the rom select
 
 Due to the limitation of Pico memory, only ROMs with a size less than or equal to **44KB** can be used.
 
+# Pre-compiled uf2
+
+https://github.com/clockworkpi/PicoCalc/blob/master/Bin/PicoCalc%20SD/firmware/PicoCalc_NES_v1.0.uf2
 
 

Code/PicoMite/README.md

@@ -14,6 +14,10 @@ make
 ```
 Copy `build/PicoMite.uf2` into picocalc like every pico device
 
+# Pre-compiled uf2
+
+https://github.com/clockworkpi/PicoCalc/blob/master/Bin/PicoCalc%20SD/firmware/PicoCalc_PicoMite_v1.0.uf2
+
 
 # MMBasic License
 

Code/uLisp/README.md

@@ -71,5 +71,6 @@ Here is the screenshot for reference:
 It should be noted that uLisp's default serial port speed is **9600**
 
 
-
+## Pre-compiled uf2
+https://github.com/clockworkpi/PicoCalc/blob/master/Bin/PicoCalc%20SD/firmware/PicoCalc_uLisp_v1.0.uf2