Update book to track quickstart changes

src/start/hardware.md

@@ -49,10 +49,10 @@ $ cargo generate --git https://github.com/rust-embedded/cortex-m-quickstart
 $ cd app
 ```
 
-Step number one is to set a default compilation target in `.cargo/config`.
+Step number one is to set a default compilation target in `.cargo/config.toml`.
 
 ``` console
-tail -n5 .cargo/config
+tail -n5 .cargo/config.toml
 ```
 
 ``` toml
@@ -320,10 +320,10 @@ OpenOCD, enable semihosting, load the program and start the process.
 
 Alternatively, you can turn `<gdb> -x openocd.gdb` into a custom runner to make
 `cargo run` build a program *and* start a GDB session. This runner is included
-in `.cargo/config` but it's commented out.
+in `.cargo/config.toml` but it's commented out.
 
 ``` console
-head -n10 .cargo/config
+head -n10 .cargo/config.toml
 ```
 
 ``` toml

src/start/qemu.md

@@ -137,11 +137,11 @@ bit in the function signature) to ensure at compile time that'll be the case.
 
 The next step is to *cross* compile the program for the Cortex-M3 architecture.
 That's as simple as running `cargo build --target $TRIPLE` if you know what the
-compilation target (`$TRIPLE`) should be. Luckily, the `.cargo/config` in the
+compilation target (`$TRIPLE`) should be. Luckily, the `.cargo/config.toml` in the
 template has the answer:
 
 ```console
-tail -n6 .cargo/config
+tail -n6 .cargo/config.toml
 ```
 
 ```toml
@@ -161,7 +161,7 @@ if you haven't done it yet:
 rustup target add thumbv7m-none-eabi
 ```
  Since the `thumbv7m-none-eabi` compilation target has been set as the default in 
- your `.cargo/config` file, the two commands below do the same:
+ your `.cargo/config.toml` file, the two commands below do the same:
 
 ```console
 cargo build --target thumbv7m-none-eabi
@@ -401,11 +401,11 @@ Let's break down that QEMU command:
   machine.
 
 Typing out that long QEMU command is too much work! We can set a custom runner
-to simplify the process. `.cargo/config` has a commented out runner that invokes
+to simplify the process. `.cargo/config.toml` has a commented out runner that invokes
 QEMU; let's uncomment it:
 
 ```console
-head -n3 .cargo/config
+head -n3 .cargo/config.toml
 ```
 
 ```toml

src/start/semihosting.md

@@ -48,7 +48,7 @@ semihosting is enabled
 QEMU understands semihosting operations so the above program will also work with
 `qemu-system-arm` without having to start a debug session. Note that you'll
 need to pass the `-semihosting-config` flag to QEMU to enable semihosting
-support; these flags are already included in the `.cargo/config` file of the
+support; these flags are already included in the `.cargo/config.toml` file of the
 template.
 
 ``` text

src/unsorted/speed-vs-size.md

@@ -148,10 +148,10 @@ closures).
 When optimizing for size you may want to try increasing the inline threshold to
 see if that has any effect on the binary size. The recommended way to change the
 inline threshold is to append the `-C inline-threshold` flag to the other
-rustflags in `.cargo/config`.
+rustflags in `.cargo/config.toml`.
 
 ``` toml
-# .cargo/config
+# .cargo/config.toml
 # this assumes that you are using the cortex-m-quickstart template
 [target.'cfg(all(target_arch = "arm", target_os = "none"))']
 rustflags = [