lint: add markdown linter (#5254)

docs/app-dev/abci-cli.md

@@ -14,7 +14,7 @@ Make sure you [have Go installed](https://golang.org/doc/install).
 
 Next, install the `abci-cli` tool and example applications:
 
-```
+```sh
 mkdir -p $GOPATH/src/github.com/tendermint
 cd $GOPATH/src/github.com/tendermint
 git clone https://github.com/tendermint/tendermint.git
@@ -25,7 +25,7 @@ make install_abci
 
 Now run `abci-cli` to see the list of commands:
 
-```
+```sh
 Usage:
   abci-cli [command]
 
@@ -69,7 +69,7 @@ Its code can be found
 [here](https://github.com/tendermint/tendermint/blob/master/abci/cmd/abci-cli/abci-cli.go)
 and looks like:
 
-```
+```go
 func cmdKVStore(cmd *cobra.Command, args []string) error {
     logger := log.NewTMLogger(log.NewSyncWriter(os.Stdout))
 
@@ -105,27 +105,27 @@ func cmdKVStore(cmd *cobra.Command, args []string) error {
 
 Start by running:
 
-```
+```sh
 abci-cli kvstore
 ```
 
 And in another terminal, run
 
-```
+```sh
 abci-cli echo hello
 abci-cli info
 ```
 
 You'll see something like:
 
-```
+```sh
 -> data: hello
 -> data.hex: 68656C6C6F
 ```
 
 and:
 
-```
+```sh
 -> data: {"size":0}
 -> data.hex: 7B2273697A65223A307D
 ```
@@ -162,7 +162,7 @@ speaking ABCI messages to your application.
 
 Try running these commands:
 
-```
+```sh
 > echo hello
 -> code: OK
 -> data: hello
@@ -226,7 +226,7 @@ Like the kvstore app, its code can be found
 [here](https://github.com/tendermint/tendermint/blob/master/abci/cmd/abci-cli/abci-cli.go)
 and looks like:
 
-```
+```sh
 func cmdCounter(cmd *cobra.Command, args []string) error {
 
     app := counter.NewCounterApplication(flagSerial)
@@ -280,13 +280,13 @@ whose integer is greater than the last committed one.
 Let's kill the console and the kvstore application, and start the
 counter app:
 
-```
+```sh
 abci-cli counter
 ```
 
 In another window, start the `abci-cli console`:
 
-```
+```sh
 > set_option serial on
 -> code: OK
 -> log: OK (SetOption doesn't return anything.)
@@ -332,7 +332,7 @@ example directory](https://github.com/tendermint/tendermint/tree/master/abci/exa
 
 To run the Node.js version, fist download & install [the Javascript ABCI server](https://github.com/tendermint/js-abci):
 
-```
+```sh
 git clone https://github.com/tendermint/js-abci.git
 cd js-abci
 npm install abci