fix: add --init vectorAdd to README linking example #156

[wenhu1024]

Linker Initialization Function

Added --init vectorAdd to explicitly specify the initialization function for the executable. Without this flag, the vectorAdd symbol was not visible in the symbol table when using llvm-readelf -s vecadd.riscv.

Key reasons for adding the flag:

• Ensures the vectorAdd function is recognized in the executable's symbol table
• Controls the program's initialization sequence
• Guarantees the correct placement of the vectorAdd symbol during linking

Before adding --init:

• llvm-readelf -s vecadd.riscv | grep vectorAdd showed no symbol

After adding --init vectorAdd:

• The symbol appears with a valid address (0x800000b8)
• Confirms successful symbol inclusion in the executable

[zhoujingya]

Goog job!