chore: update README regarding `svelteConfig` #4030

Job	Run time
lint	3m 44s
build	1m 22s
Test for Svelte v3 (ubuntu-latest, 18)	49s
Test for ESLint 8 on Node.js: 22.x OS: ubuntu-latest	1m 23s
Test for ESLint 8 on Node.js: 20.x OS: ubuntu-latest	1m 27s
Test for Svelte v4 on Node.js: 20 OS: ubuntu-latest	49s
Test for ESLint 8 on Node.js: latest OS: ubuntu-latest	1m 24s
Test for Svelte v4 on Node.js: 22 OS: ubuntu-latest	54s
Test for ESLint 8 on Node.js: 18.x OS: ubuntu-latest	1m 35s
Test for ESLint 9 on Node.js: 18.x OS: ubuntu-latest	1m 33s
Test for Svelte v4 on Node.js: 18 OS: ubuntu-latest	1m 4s
Test for ESLint 9 on Node.js: latest OS: ubuntu-latest	1m 23s
update-resources	38s
Test for ESLint 9 on Node.js: 20.x OS: ubuntu-latest	1m 26s
Test for ESLint 9 on Node.js: 22.x OS: ubuntu-latest	1m 19s
	20m 50s

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