doc/languages-frameworks/*: add missing languages to code fences

convert shell -> ShellSession

doc/languages-frameworks/rust.section.md

@@ -2,13 +2,14 @@
 
 To install the rust compiler and cargo put
 
-```
-rustc
-cargo
+```nix
+environment.systemPackages = [
+  rustc
+  cargo
+];
 ```
 
-into the `environment.systemPackages` or bring them into
-scope with `nix-shell -p rustc cargo`.
+into your `configuration.nix` or bring them into scope with `nix-shell -p rustc cargo`.
 
 For other versions such as daily builds (beta and nightly),
 use either `rustup` from nixpkgs (which will manage the rust installation in your home directory),
@@ -18,7 +19,7 @@ or use Mozilla's [Rust nightlies overlay](#using-the-rust-nightlies-overlay).
 
 Rust applications are packaged by using the `buildRustPackage` helper from `rustPlatform`:
 
-```
+```nix
 { lib, rustPlatform }:
 
 rustPlatform.buildRustPackage rec {
@@ -49,7 +50,7 @@ package. `cargoHash256` is used for traditional Nix SHA-256 hashes,
 such as the one in the example above. `cargoHash` should instead be
 used for [SRI](https://www.w3.org/TR/SRI/) hashes. For example:
 
-```
+```nix
   cargoHash = "sha256-l1vL2ZdtDRxSGvP0X/l3nMw8+6WF67KPutJEzUROjg8=";
 ```
 
@@ -59,13 +60,13 @@ expression and building the package once. The correct checksum can
 then be taken from the failed build. A fake hash can be used for
 `cargoSha256` as follows:
 
-```
+```nix
   cargoSha256 = lib.fakeSha256;
 ```
 
 For `cargoHash` you can use:
 
-```
+```nix
   cargoHash = lib.fakeHash;
 ```
 
@@ -255,7 +256,7 @@ Otherwise, some steps may fail because of the modified directory structure of `t
 source code in a reproducible way. If it is missing or out-of-date one can use
 the `cargoPatches` attribute to update or add it.
 
-```
+```nix
 rustPlatform.buildRustPackage rec {
   (...)
   cargoPatches = [
@@ -481,7 +482,7 @@ an example for a minimal `hello` crate:
 
 Now, the file produced by the call to `carnix`, called `hello.nix`, looks like:
 
-```
+```nix
 # Generated by carnix 0.6.5: carnix -o hello.nix --src ./. Cargo.lock --standalone
 { stdenv, buildRustCrate, fetchgit }:
 let kernel = stdenv.buildPlatform.parsed.kernel.name;
@@ -510,7 +511,7 @@ dependencies, for instance by adding a single line `libc="*"` to our
 `Cargo.lock`. Then, `carnix` needs to be run again, and produces the
 following nix file:
 
-```
+```nix
 # Generated by carnix 0.6.5: carnix -o hello.nix --src ./. Cargo.lock --standalone
 { stdenv, buildRustCrate, fetchgit }:
 let kernel = stdenv.buildPlatform.parsed.kernel.name;
@@ -565,7 +566,7 @@ Some crates require external libraries. For crates from
 Starting from that file, one can add more overrides, to add features
 or build inputs by overriding the hello crate in a seperate file.
 
-```
+```nix
 with import <nixpkgs> {};
 ((import ./hello.nix).hello {}).override {
   crateOverrides = defaultCrateOverrides // {
@@ -585,7 +586,7 @@ derivation depend on the crate's version, the `attrs` argument of
 the override above can be read, as in the following example, which
 patches the derivation:
 
-```
+```nix
 with import <nixpkgs> {};
 ((import ./hello.nix).hello {}).override {
   crateOverrides = defaultCrateOverrides // {
@@ -606,7 +607,7 @@ dependencies. For instance, to override the build inputs for crate
 `libc` in the example above, where `libc` is a dependency of the main
 crate, we could do:
 
-```
+```nix
 with import <nixpkgs> {};
 ((import hello.nix).hello {}).override {
   crateOverrides = defaultCrateOverrides // {
@@ -622,27 +623,27 @@ general. A number of other parameters can be overridden:
 
 - The version of rustc used to compile the crate:
 
-  ```
+  ```nix
   (hello {}).override { rust = pkgs.rust; };
   ```
 
 - Whether to build in release mode or debug mode (release mode by
   default):
 
-  ```
+  ```nix
   (hello {}).override { release = false; };
   ```
 
 - Whether to print the commands sent to rustc when building
   (equivalent to `--verbose` in cargo:
 
-  ```
+  ```nix
   (hello {}).override { verbose = false; };
   ```
 
 - Extra arguments to be passed to `rustc`:
 
-  ```
+  ```nix
   (hello {}).override { extraRustcOpts = "-Z debuginfo=2"; };
   ```
 
@@ -654,7 +655,7 @@ general. A number of other parameters can be overridden:
   `postInstall`. As an example, here is how to create a new module
   before running the build script:
 
-  ```
+  ```nix
   (hello {}).override {
     preConfigure = ''
        echo "pub const PATH=\"${hi.out}\";" >> src/path.rs"
@@ -668,7 +669,7 @@ One can also supply features switches. For example, if we want to
 compile `diesel_cli` only with the `postgres` feature, and no default
 features, we would write:
 
-```
+```nix
 (callPackage ./diesel.nix {}).diesel {
   default = false;
   postgres = true;
@@ -691,7 +692,7 @@ Using the example `hello` project above, we want to do the following:
 
 A typical `shell.nix` might look like:
 
-```
+```nix
 with import <nixpkgs> {};
 
 stdenv.mkDerivation {
@@ -713,7 +714,7 @@ stdenv.mkDerivation {
 ```
 
 You should now be able to run the following:
-```
+```ShellSesssion
 $ nix-shell --pure
 $ cargo build
 $ cargo test
@@ -723,7 +724,7 @@ $ cargo test
 To control your rust version (i.e. use nightly) from within `shell.nix` (or
 other nix expressions) you can use the following `shell.nix`
 
-```
+```nix
 # Latest Nightly
 with import <nixpkgs> {};
 let src = fetchFromGitHub {
@@ -751,7 +752,7 @@ stdenv.mkDerivation {
 ```
 
 Now run:
-```
+```ShellSession
 $ rustc --version
 rustc 1.26.0-nightly (188e693b3 2018-03-26)
 ```
@@ -786,7 +787,7 @@ in the `~/.config/nixpkgs/overlays` directory.
 
 Add the following to your `configuration.nix`, `home-configuration.nix`, `shell.nix`, or similar:
 
-```
+```nix
 { pkgs ? import <nixpkgs> {
     overlays = [
       (import (builtins.fetchTarball https://github.com/mozilla/nixpkgs-mozilla/archive/master.tar.gz))