Adjust bibliography database to be similar to the RISC-V ISA manual

doc/rvv-intrinsics.bib

@@ -1,6 +1,6 @@
-@misc{riscv-asm-manual,
+@electronic{riscv-asm-manual,
   title = {{RISC-V Assembly Programmer's Manual}},
-  howpublished = {\url{https://github.com/riscv/riscv-asm-manual}},
+  url = {https://github.com/riscv/riscv-asm-manual},
   year = {}
 }
 
@@ -10,26 +10,26 @@ @electronic{riscv-v-spec
   year = {}
 }
 
-@misc{riscv-c-api,
+@electronic{riscv-c-api,
   title = {{RISC-V C API Specification}},
-  howpublished = {\url{https://github.com/riscv-non-isa/riscv-c-api-doc/blob/master/riscv-c-api.md}},
+  url = {https://github.com/riscv-non-isa/riscv-c-api-doc/blob/master/riscv-c-api.md},
   year = {}
 }
 
-@misc{riscv-guide-llvm,
+@electronic{riscv-guide-llvm,
   title = {{User Guide for RISC-V Target}},
-  howpublished = {\url{https://llvm.org/docs/RISCVUsage.html}},
+  url = {\url{https://llvm.org/docs/RISCVUsage.html}},
   year = {}
 }
 
-@misc{riscv-v-gcc,
+@electronic{riscv-v-gcc,
   title = {{RISC-V Options}},
-  howpublished = {\url{https://gcc.gnu.org/onlinedocs/gcc/RISC-V-Options.html}},
+  url = {https://gcc.gnu.org/onlinedocs/gcc/RISC-V-Options.html},
   year = {}
 }
 
-@misc{riscv-cc-vector,
+@electronic{riscv-cc-vector,
   title = {{RISC-V Calling Conventions: Vector}},
-  howpublished = {\url{https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-cc.adoc#vector-register-convention}},
+  url = {https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-cc.adoc#vector-register-convention},
   year = {}
 }