Add lib es2015 to tsconfig

[SHND]

Fixing an issue when running tsc inside the examples directory from a newly cloned repo, it errors out like below:

node_modules/ts-pattern/dist/types/BuildMany.d.ts:18:110 - error TS2583: Cannot find name 'Set'. Do you need to change your target library? Try changing the 'lib' compiler option to 'es2015' or later.

18 ] : never : data extends readonly (infer a)[] ? Update<a, value, Cast<tail, PropertyKey[]>>[] : data extends Set<infer a> ? Set<Update<a, value, Cast<tail, PropertyKey[]>>> : data extends Map<infer k, infer v> ? Map<k, Update<v, value, Cast<tail, PropertyKey[]>>> : Compute<Omit<data, Cast<head, PropertyKey>> & {
                                                                                                                ~~~

node_modules/ts-pattern/dist/types/BuildMany.d.ts:18:125 - error TS2583: Cannot find name 'Set'. Do you need to change your target library? Try changing the 'lib' compiler option to 'es2015' or later.

18 ] : never : data extends readonly (infer a)[] ? Update<a, value, Cast<tail, PropertyKey[]>>[] : data extends Set<infer a> ? Set<Update<a, value, Cast<tail, PropertyKey[]>>> : data extends Map<infer k, infer v> ? Map<k, Update<v, value, Cast<tail, PropertyKey[]>>> : Compute<Omit<data, Cast<head, PropertyKey>> & {
...

How to reproduce

tsc Version 4.8.4
node Version v16.13.1
npm Version 8.1.2

cd ts-pattern/examples
npm install
tsc

[gvergnaud]

Thanks!