Create eslint and prettier configuration for TS

[jorgenbele]

The README states that this project uses prettier to format all typescript code, but the default prettier configuration does not match the formatting style used thus far. This PR matches better than the default configuration.

Based on (but modified slightly): https://www.robertcooper.me/using-eslint-and-prettier-in-a-typescript-project

[jorgenbele]

Reformatting all code under src/ results in:

 src/App.test.tsx                                   |  10 +-
 src/App.tsx                                        |  14 +-
 src/auth.tsx                                       |   2 +-
 src/colorscheme.css                                |  38 ++--
 src/components/dialogue/Dialogue.tsx               |  47 ++--
 src/components/filterBuilder/FilterBuilder.css     |  10 +-
 src/components/filterBuilder/filterBuilder.tsx     | 188 +++++++--------
 src/components/header/Header.css                   | 253 ++++++++++-----------
 src/components/header/Header.tsx                   |  68 +++---
 src/components/profile/Profile.css                 |  17 +-
 src/components/profile/Profile.tsx                 | 134 +++++------
 src/components/profileList/ProfileList.css         |   5 +-
 src/components/profileList/ProfileList.tsx         |  66 +++---
 src/components/react-table/Table.tsx               |  48 ++--
 src/components/react-table/table.css               | 157 +++++++------
 src/components/spinners/Spinner.tsx                |  20 +-
 .../time-interval-select/TimeInterval.tsx          |  88 ++++---
 .../time-interval-select/timeInterval.css          |  62 +++--
 src/components/time-interval/TimeIntervals.tsx     |  78 ++-----
 src/components/time-slot/TimeSlot.tsx              |  81 ++++---
 src/handleFeide.tsx                                |  22 +-
 src/index.css                                      |  12 +-
 src/index.tsx                                      |  16 +-
 src/protected.route.tsx                            |  42 ++--
 src/serviceWorker.ts                               |  54 ++---
 src/store.tsx                                      |  19 +-
 src/variables.css                                  |  10 +-
 src/views/alertView/AlertView.tsx                  |  35 ++-
 .../filterBuildingView/filterBuildingView.tsx      |  14 +-
 src/views/loginView/LoginView.css                  |  23 +-
 src/views/loginView/LoginView.tsx                  | 100 ++++----
 .../NotificationProfileView.tsx                    |  12 +-
 32 files changed, 796 insertions(+), 949 deletions(-)

We might be able to reduce the amount of necessary changes by tinkering with prettier.

[havfo]

Looks good