chore: remove "flow" references

Author: mdjastrzebski

.eslintrc

@@ -1,7 +1,6 @@
 {
   "extends": "@callstack",
   "rules": {
-    "flowtype/no-weak-types": 0,
     "react-native/no-raw-text": 0,
     "no-console": 1,
     "react/no-multi-comp": 0,

CONTRIBUTING.md

@@ -32,9 +32,9 @@ Our pre-commit hooks verify that your commit message matches this format when co
 
 ### Linting and tests
 
-We use `flow` for type checking, `eslint` with `prettier` for linting and formatting the code, and `jest` for testing. Our pre-commit hooks verify that the linter and tests pass when committing. You can also run the following commands manually:
+We use TypeScript for type checking, `eslint` with `prettier` for linting and formatting the code, and `jest` for testing. Our pre-commit hooks verify that the linter and tests pass when committing. You can also run the following commands manually:
 
-- `yarn flow`: run flow on all files.
+- `yarn typecheck`: run TypeScript compiler on all files.
 - `yarn lint`: run eslint and prettier.
 - `yarn test`: run tests.
 
@@ -43,7 +43,7 @@ We use `flow` for type checking, `eslint` with `prettier` for linting and format
 When you're sending a pull request:
 
 - Prefer small pull requests focused on one change.
-- Verify that `flow`, `eslint` and tests are passing.
+- Verify that `typecheck`, `eslint` and tests are passing.
 - Preview the documentation to make sure it looks good.
 - Follow the pull request template when opening a pull request.