readme: Remove unused images

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

readme/images/Font_style.PNG.license

-SPDX-FileCopyrightText: Huawei Inc.
-
-SPDX-License-Identifier: CC-BY-4.0

readme/images/List-table.PNG.license

-SPDX-FileCopyrightText: Huawei Inc.
-
-SPDX-License-Identifier: CC-BY-4.0
\ No newline at end of file

readme/images/List.PNG.license

-SPDX-FileCopyrightText: Huawei Inc.
-
-SPDX-License-Identifier: CC-BY-4.0
\ No newline at end of file

readme/images/csv_table.PNG.license

-SPDX-FileCopyrightText: Huawei Inc.
-
-SPDX-License-Identifier: CC-BY-4.0
\ No newline at end of file

readme/images/math.PNG.license

-SPDX-FileCopyrightText: Huawei Inc.
-
-SPDX-License-Identifier: CC-BY-4.0
\ No newline at end of file

readme/images/multi-column_list.PNG.license

-SPDX-FileCopyrightText: Huawei Inc.
-
-SPDX-License-Identifier: CC-BY-4.0
\ No newline at end of file

readme/images/multi_data.PNG.license

-SPDX-FileCopyrightText: Huawei Inc.
-
-SPDX-License-Identifier: CC-BY-4.0
\ No newline at end of file

readme/images/quick-start.PNG.license

-SPDX-FileCopyrightText: Huawei Inc.
-
-SPDX-License-Identifier: CC-BY-4.0
\ No newline at end of file

readme/images/tables.PNG.license

-SPDX-FileCopyrightText: Huawei Inc.
-
-SPDX-License-Identifier: CC-BY-4.0
\ No newline at end of file