Add convenience inline links to README.md (#7061)

Signed-off-by: Elsie Hupp <9206310+elsiehupp@users.noreply.github.com>

README.md

@@ -11,7 +11,7 @@ a 'skin'. A skin provides:
  * The containing application
  * Zero or more 'modules' containing non-UI functionality
 
-As of Aug 2018, the only skin that exists is `vector-im/element-web`; it and
+As of Aug 2018, the only skin that exists is [`vector-im/element-web`](https://github.com/vector-im/element-web/); it and
 `matrix-org/matrix-react-sdk` should effectively
 be considered as a single project (for instance, matrix-react-sdk bugs
 are currently filed against vector-im/element-web rather than this project).
@@ -138,7 +138,7 @@ guide](https://classic.yarnpkg.com/docs/install) if you do not have it
 already. This project has not yet been migrated to Yarn 2, so please ensure
 `yarn --version` shows a version from the 1.x series.
 
-`matrix-react-sdk` depends on `matrix-js-sdk`. To make use of changes in the
+`matrix-react-sdk` depends on [`matrix-js-sdk`](https://github.com/matrix-org/matrix-js-sdk). To make use of changes in the
 latter and to ensure tests run against the develop branch of `matrix-js-sdk`,
 you should set up `matrix-js-sdk`:
 
@@ -175,4 +175,4 @@ yarn test
 ## End-to-End tests
 
 Make sure you've got your Element development server running (by doing `yarn start` in element-web), and then in this project, run `yarn run e2etests`.
-See `test/end-to-end-tests/README.md` for more information.
+See [`test/end-to-end-tests/README.md`](https://github.com/matrix-org/matrix-react-sdk/blob/develop/test/end-to-end-tests/README.md) for more information.