Doc EN : props vs "props" in passing-props for better comprehension. (#1597)

* Remove unnecessary new line

Signed-off-by: Bruno Lesieur <bruno.lesieur@gmail.com>

* Update dev

* Use coerce word in replacement of cast.
Differetiate usage of `props` to speak about `props` options and "props" to speak about the props concept.

Signed-off-by: Bruno Lesieur <bruno.lesieur@gmail.com>

* Update passing-props.md

Author: MachinisteWeb

docs/en/essentials/passing-props.md

@@ -1,10 +1,10 @@
 # Passing Props to Route Components
 
-Using `$route` in your component creates a tight coupling with the route which limits the flexibility of the component as it can only be used on certain urls.
+Using `$route` in your component creates a tight coupling with the route which limits the flexibility of the component as it can only be used on certain URLs.
 
-To decouple this component from the router use props:
+To decouple this component from the router use option `props`:
 
-**❌ Coupled to $route**
+**❌ Coupled to `$route`**
 
 ``` js
 const User = {
@@ -17,7 +17,7 @@ const router = new VueRouter({
 })
 ```
 
-**👍 Decoupled with props**
+**👍 Decoupled with `props`**
 
 ``` js
 const User = {
@@ -28,7 +28,7 @@ const router = new VueRouter({
   routes: [
     { path: '/user/:id', component: User, props: true }
 
-    // for routes with named views, you have to define the props option for each named view:
+    // for routes with named views, you have to define the `props` option for each named view:
     {
       path: '/user/:id',
       components: { default: User, sidebar: Sidebar },
@@ -42,12 +42,11 @@ This allows you to use the component anywhere, which makes the component easier
 
 ### Boolean mode
 
-When props is set to true, the route.params will be set as the component props.
+When `props` is set to `true`, the `route.params` will be set as the component props.
 
 ### Object mode
 
-When props is an object, this will be set as the component props as-is.
-Useful for when the props are static.
+When `props` is an object, this will be set as the component props as-is. Useful for when the props are static.
 
 ``` js
 const router = new VueRouter({
@@ -59,7 +58,7 @@ const router = new VueRouter({
 
 ### Function mode
 
-You can create a function that returns props. This allows you to cast the parameter to another type, combine static values with route-based values, etc.
+You can create a function that returns props. This allows you to cast parameters into other types, combine static values with route-based values, etc.
 
 ``` js
 const router = new VueRouter({
@@ -69,8 +68,8 @@ const router = new VueRouter({
 })
 ```
 
-The url: `/search?q=vue` would pass `{query: "vue"}` as props to the SearchUser component.
+The URL `/search?q=vue` would pass `{query: 'vue'}` as props to the `SearchUser` component.
 
-Try to keep the props function stateless, as it's only evaluated on route changes. Use a wrapper component if you need state to define the props, that way vue can react to state changes.
+Try to keep the `props` function stateless, as it's only evaluated on route changes. Use a wrapper component if you need state to define the props, that way vue can react to state changes.
 
 For advanced usage, checkout the [example](https://github.com/vuejs/vue-router/blob/dev/examples/route-props/app.js).