Update docs (#13309)

docs/install.md

@@ -30,7 +30,7 @@ echo {}> .prettierrc.json
 
 Next, create a [.prettierignore](ignore.md) file to let the Prettier CLI and editors know which files to _not_ format. Here’s an example:
 
-```
+```text
 # Ignore artifacts:
 build
 coverage
@@ -46,7 +46,7 @@ Now, format all files with Prettier:
 <!--npm-->
 
 ```bash
-npx prettier --write .
+npx prettier . --write
 ```
 
 > What is that `npx` thing? `npx` ships with `npm` and lets you run locally installed tools. We’ll leave off the `npx` part for brevity throughout the rest of this file!
@@ -56,7 +56,7 @@ npx prettier --write .
 <!--yarn-->
 
 ```bash
-yarn prettier --write .
+yarn prettier . --write
 ```
 
 > What is `yarn` doing at the start? `yarn prettier` runs the locally installed version of Prettier. We’ll leave off the `yarn` part for brevity throughout the rest of this file!
@@ -68,7 +68,7 @@ yarn prettier --write .
 If you have a CI setup, run the following as part of it to make sure that everyone runs Prettier. This avoids merge conflicts and other collaboration issues!
 
 ```bash
-npx prettier --check .
+npx prettier . --check
 ```
 
 `--check` is like `--write`, but only checks that files are already formatted, rather than overwriting them. `prettier --write` and `prettier --check` are the most common ways to run Prettier.