Remove unknown languages from code block fences

Author: senekor

content/Rust-1.15.md

@@ -78,7 +78,7 @@ fn main() {
 
 This will output:
 
-```text
+```
 serialized = {"name":"Ferris"}
 deserialized = Pet { name: "Ferris" }
 ```

content/Rust-1.16.md

@@ -34,7 +34,7 @@ What does it do? Let's take a step back and talk about how `rustc` compiles your
 to producing the final binary. You can see each of these steps (and how much time and memory they take)
 by passing `-Z time-passes` to a nightly compiler:
 
- ```text
+ ```
  rustc +nightly hello.rs -Z time-passes
 time: 0.003; rss: 16MB  parsing
 time: 0.000; rss: 16MB  recursion limit
@@ -195,7 +195,7 @@ println!("{}", ffo);
 
 Would give this error:
 
-```text
+```
 error[E0425]: cannot find value `ffo` in this scope
  --> foo.rs:4:20
   |
@@ -277,7 +277,7 @@ When slicing a `&str`, [you'll see better errors]. For example, this code:
 
 Is incorrect. It generates this error:
 
-```text
+```
 thread 'str::test_slice_fail_boundary_1' panicked at 'byte index 4 is not
 a char boundary; it is inside 'α' (bytes 3..5) of `abcαβγ`'
 ```

content/Rust-1.17.md

@@ -234,7 +234,7 @@ your preferences.
 Backtraces [now have nicer formatting](https://github.com/rust-lang/rust/pull/38165), eliding
 some things by default. For example, the full backtrace:
 
-```text
+```
 thread 'main' panicked at 'explicit panic', foo.rs:2
 stack backtrace:
    1:     0x55c39a23372c - std::sys::imp::backtrace::tracing::imp::write::hf33ae72d0baa11ed
@@ -261,7 +261,7 @@ stack backtrace:
 
 is now instead
 
-```text
+```
 thread 'main' panicked at 'explicit panic', foo.rs:2
 stack backtrace:
    0: std::sys::imp::backtrace::tracing::imp::unwind_backtrace

content/Rust-1.20.md

@@ -186,7 +186,7 @@ Stability is a property of sorting algorithms that may or may not matter to you,
 but now you have both options! Here's a brief summary: imagine we had a list
 of words like this:
 
-```text
+```
 rust
 crate
 package
@@ -196,7 +196,7 @@ cargo
 Two of these words, `cargo` and `crate`, both start with the letter `c`. A stable
 sort that sorts only on the first letter must produce this result:
 
-```text
+```
 crate
 cargo
 package
@@ -207,7 +207,7 @@ That is, because `crate` came before `cargo` in the original list, it must also
 before it in the final list. An unstable sort could provide that result, but could
 also give this answer too:
 
-```text
+```
 cargo
 crate
 package

content/Rust-1.21.md

@@ -65,7 +65,7 @@ fn main() {
 
 In previous versions of Rust, this would fail to compile:
 
-```text
+```
 error[E0597]: borrowed value does not live long enough
   --> src/main.rs:4:14
    |

content/Rust-1.26.1.md

@@ -126,7 +126,7 @@ component, but this should be a one-time problem.
 This was unfortunately fixed too late to make it into 1.26 stable, so we added
 the patch for 1.26.1 to permit users to install Rust on these platforms.
 
-```console
+```
 $ rustup update
 info: syncing channel updates for 'stable-x86_64-unknown-freebsd'
 info: latest update on 2018-05-10, rust version 1.26.0 (a77568041 2018-05-07)

content/Rust-1.26.md

@@ -155,7 +155,7 @@ fn foo() {
 
 when compiled, gives this error:
 
-```text
+```
 error[E0308]: mismatched types
  --> src/main.rs:5:5
   |
@@ -241,7 +241,7 @@ fn hello(arg: &Option<String>) {
 
 If you tried to compile this in Rust 1.25, you'd get this error:
 
-```text
+```
 error[E0658]: non-reference pattern used to match a reference (see issue #42640)
  --> src/main.rs:6:9
   |
@@ -268,7 +268,7 @@ fn hello(arg: &Option<String>) {
 
 We added the `&`s the compiler complained about. Let's try to compile again:
 
-```text
+```
 error[E0507]: cannot move out of borrowed content
  --> src/main.rs:6:9
   |
@@ -421,7 +421,7 @@ fn main() {
 What does this program do? The answer: nothing. The warning we get when
 compiling has a hint:
 
-```text
+```
 warning: literal out of range for u8
  --> src/main.rs:6:17
   |

content/Rust-1.27.1.md

@@ -14,7 +14,7 @@ systems programming language focused on safety, speed, and concurrency.
 If you have a previous version of Rust installed via rustup, getting Rust
 1.27.1 is as easy as:
 
-```console
+```
 $ rustup update stable
 ```
 

content/Rust-1.29.1.md

@@ -14,7 +14,7 @@ systems programming language focused on safety, speed, and concurrency.
 If you have a previous version of Rust installed via rustup, getting Rust
 1.29.1 is as easy as:
 
-```console
+```
 $ rustup update stable
 ```
 

content/Rust-1.29.2.md

@@ -14,7 +14,7 @@ systems programming language focused on safety, speed, and concurrency.
 If you have a previous version of Rust installed via rustup, getting Rust
 1.29.2 is as easy as:
 
-```console
+```
 $ rustup update stable
 ```