Fix: format all the stuff

src/dev/golang/testing.md

@@ -31,6 +31,7 @@ or
 ```golang
 t.Logf()
 ```
+
 also,
 
 ```shell
@@ -44,6 +45,7 @@ go test github.com/go/pkg/package -v
 ```golang
 t.Fail()
 ```
+
 ### Mark test as failed AND exit
 
 ```golang

src/dev/rust/serde.md

@@ -4,7 +4,6 @@
 
 For example, this can be used to deserialize toml into a dedicated struct.
 
-
 ## Example, with toml
 
 Here is how serde after version 1.0 (included) should be used with serialize/deserialize mechanisms.

src/ops/tools/mongodb.md

@@ -13,4 +13,3 @@ Reality says
 ```shell
 mongo --username user --password='passwd'
 ```
-