docs: fix typos and update https references (#8154)

Co-authored-by: Tim Lai <timothy.lai@smartbear.com>

src/core/components/object-model.jsx

@@ -103,7 +103,7 @@ export default class ObjectModel extends Component {
                       true
                     </td>
                   </tr>
-               
+
               }
               {
                 !(properties && properties.size) ? null : properties.entrySeq().filter(
@@ -143,7 +143,7 @@ export default class ObjectModel extends Component {
                     }).toArray()
               }
               {
-                // empty row befor extensions...
+                // empty row before extensions...
                 !showExtensions ? null : <tr><td>&nbsp;</td></tr>
               }
               {

src/core/plugins/oas3/helpers.jsx

@@ -6,7 +6,7 @@ export function isOAS3(jsSpec) {
     return false
   }
 
-  // we gate against `3.1` becasue we want to explicitly opt into supporting it
+  // we gate against `3.1` because we want to explicitly opt into supporting it
   // at some point in the future -- KS, 7/2018
 
   // starts with, but is not `3.0.` exactly

src/plugins/add-plugin.md

@@ -66,7 +66,7 @@ export function SomePlugin(toolbox) {
             getState => getState(), // This is a requirement... because we `bind` selectors, we don't want to bind to any particular state (which is an immutable value) so we bind to a function, which returns the current state
             state => state.get("something") // return the whatever "something" points to
           ),
-          foo: getState => "bar" // In the end selectors are just fuctions that we pass getState to
+          foo: getState => "bar" // In the end selectors are just functions that we pass getState to
         }
       }