chore(*): remove ISSUE_TEMPLATE in favor of centralized template (#311)

This pull request removes outdated issue templates and updates the
`.github/sync-client.yml` configuration file to reflect these deletions.
The changes streamline the repository by eliminating unused files and
their associated synchronization rules.

### Removal of outdated issue templates:
* Deleted the `1-bug.md` issue template, which was used for reporting
bugs or regressions.
* Deleted the `2-suggestion.md` issue template, which was used for
suggesting new features or improvements.
* Deleted the `3-others.md` issue template, which was used for reporting
miscellaneous issues.

### Update to synchronization configuration:
* Removed references to the deleted issue templates in the
`.github/sync-client.yml` file, ensuring synchronization rules are
consistent with the current file structure.

Author: lumirlumir

.github/ISSUE_TEMPLATE/1-bug.md

@@ -1,13 +1,6 @@
 lumirlumir/lumirlumir-configs:
   - source: ./.github/sync-client.yml
     dest: ./clients/npm-textlint-rule-allowed-uris.yml
-  # ./.github/ISSUE_TEMPLATE
-  - source: ./.github/ISSUE_TEMPLATE/1-bug.md
-    dest: ./configs/.github/ISSUE_TEMPLATE/1-bug.md
-  - source: ./.github/ISSUE_TEMPLATE/2-suggestion.md
-    dest: ./configs/.github/ISSUE_TEMPLATE/2-suggestion.md
-  - source: ./.github/ISSUE_TEMPLATE/3-others.md
-    dest: ./configs/.github/ISSUE_TEMPLATE/3-others.md
   # ./.github/workflows
   - source: ./.github/workflows/lint.yml
     dest: ./configs/.github/workflows/lint.yml