Escape all * in rustc's SUMMARY.md

Author: tbu-

src/doc/rustc/src/SUMMARY.md

@@ -67,8 +67,8 @@
     - [powerpc-unknown-linux-muslspe](platform-support/powerpc-unknown-linux-muslspe.md)
     - [powerpc64-ibm-aix](platform-support/aix.md)
     - [powerpc64le-unknown-linux-musl](platform-support/powerpc64le-unknown-linux-musl.md)
-    - [riscv32e*-unknown-none-elf](platform-support/riscv32e-unknown-none-elf.md)
-    - [riscv32i*-unknown-none-elf](platform-support/riscv32-unknown-none-elf.md)
+    - [riscv32e\*-unknown-none-elf](platform-support/riscv32e-unknown-none-elf.md)
+    - [riscv32i\*-unknown-none-elf](platform-support/riscv32-unknown-none-elf.md)
     - [riscv32im-risc0-zkvm-elf](platform-support/riscv32im-risc0-zkvm-elf.md)
     - [riscv32imac-unknown-xous-elf](platform-support/riscv32imac-unknown-xous-elf.md)
     - [riscv64gc-unknown-linux-gnu](platform-support/riscv64gc-unknown-linux-gnu.md)
@@ -77,13 +77,13 @@
     - [s390x-unknown-linux-musl](platform-support/s390x-unknown-linux-musl.md)
     - [sparc-unknown-none-elf](./platform-support/sparc-unknown-none-elf.md)
     - [sparcv9-sun-solaris](platform-support/solaris.md)
-    - [*-pc-windows-gnullvm](platform-support/pc-windows-gnullvm.md)
+    - [\*-pc-windows-gnullvm](platform-support/pc-windows-gnullvm.md)
     - [\*-nto-qnx-\*](platform-support/nto-qnx.md)
-    - [*-unikraft-linux-musl](platform-support/unikraft-linux-musl.md)
-    - [*-unknown-hermit](platform-support/hermit.md)
+    - [\*-unikraft-linux-musl](platform-support/unikraft-linux-musl.md)
+    - [\*-unknown-hermit](platform-support/hermit.md)
     - [\*-unknown-netbsd\*](platform-support/netbsd.md)
-    - [*-unknown-openbsd](platform-support/openbsd.md)
-    - [*-unknown-redox](platform-support/redox.md)
+    - [\*-unknown-openbsd](platform-support/openbsd.md)
+    - [\*-unknown-redox](platform-support/redox.md)
     - [\*-unknown-uefi](platform-support/unknown-uefi.md)
     - [\*-wrs-vxworks](platform-support/vxworks.md)
     - [wasm32-wasip1](platform-support/wasm32-wasip1.md)
@@ -99,7 +99,7 @@
     - [x86_64-unknown-linux-none.md](platform-support/x86_64-unknown-linux-none.md)
     - [x86_64-unknown-none](platform-support/x86_64-unknown-none.md)
     - [xtensa-\*-none-elf](platform-support/xtensa.md)
-    - [*-nuttx-\*](platform-support/nuttx.md)
+    - [\*-nuttx-\*](platform-support/nuttx.md)
 - [Targets](targets/index.md)
     - [Built-in Targets](targets/built-in.md)
     - [Custom Targets](targets/custom.md)