Improve I18N Issues (Based on 1.3.99)

I found several I18N issues and made necessary modifications, then I listed them as the following.

All modifications should be implemented to include\rtoc_admin.php.

Line 8

__( 'RTOC Admin Screen', 'rich-table-of-content' ),

Line 295 to 298

'ul'   => '<ul class="c-list-style"><li><span class="c-admin-round">' . esc_html__( 'H2 TITLE', 'rich-table-of-content' ) . '</span></li><li>' . $rtoc_design_round . '</li></ul>',
'ol'   => '<ul class="c-list-style"><li><span class="c-admin-number">1.</span>' . esc_html__( 'H2 TITLE', 'rich-table-of-content' ) . '</li><li>' . $rtoc_design_number1 . '</li></ul>',
'ol2'  => '<ul class="c-list-style"><li><span class="c-admin-decimal">01</span>' . esc_html__( 'H2 TITLE', 'rich-table-of-content' ) . '</li><li>' . $rtoc_design_number2 . '</li></ul>',
'none' => '<ul class="c-list-style"><li>' . esc_html__( 'H2 TITLE', 'rich-table-of-content' ) . '</li><li>' . $rtoc_design_none . '</li></ul>'

Line 312 to 313, 343 to 344, 398 to 399, 435 to 436, 509 to 510, 620 to 621

'on'  => __( 'ON', 'rich-table-of-content' ),
'off' => __( 'OFF', 'rich-table-of-content' ),

Line 326 to 329

'ul'   => '<ul class="c-list-style"><li><span class="c-admin-round">' . esc_html__( 'H3 TITLE', 'rich-table-of-content' ) . '</span></li><li>' . $rtoc_design_round . '</li></ul>',
'ol'   => '<ul class="c-list-style"><li><span class="c-admin-number">1.</span>' . esc_html__( 'H3 TITLE', 'rich-table-of-content' ) . '</li><li>' . $rtoc_design_number1 . '</li></ul>',
'ol2'  => '<ul class="c-list-style"><li><span class="c-admin-decimal">01</span>' . esc_html__( 'H3 TITLE', 'rich-table-of-content' ) . '</li><li>' . $rtoc_design_number2 . '</li></ul>',
'none' => '<ul class="c-list-style"><li>' . esc_html__( 'H3 TITLE', 'rich-table-of-content' ) . '</li><li>' . $rtoc_design_none . '</li></ul>'

Line 809

update_option('rtoc_title', __( 'Contents', 'rich-table-of-content' ));

Line 813 to 814

'<input type="text" placeholder="%s" id="rtoc_title" name="rtoc_title" value="%s" class="rtoc_admin_text" />',
esc_attr__( 'CONTENTS', 'rich-table-of-content' ),isset($option) ? esc_attr($option) : ''

Line 909

update_option('rtoc_open_text', __( 'OPEN', 'rich-table-of-content' ));

Line 913 to 914

'<input type="text" placeholder="%s" id="rtoc_open_text" name="rtoc_open_text" value="%s" class="rtoc_admin_text" />',
esc_attr__( 'OPEN', 'rich-table-of-content' ), isset($option) ? esc_attr($option) : ''

Line 921

update_option('rtoc_close_text', __( 'CLOSE', 'rich-table-of-content' ));

Line 925 to 926

'<input type="text" placeholder="%s" id="rtoc_close_text" name="rtoc_close_text" value="%s" class="rtoc_admin_text" />',
esc_attr__( 'CLOSE', 'rich-table-of-content' ), isset($option) ? esc_attr($option) : ''

Line 1151 to 1152

'<input type="text" placeholder="%s" id="rtoc_back_text" name="rtoc_back_text" value="%s" class="rtoc_admin_text" />',
esc_attr__('TOC', 'rich-table-of-content'), isset($option) ? esc_attr($option) : ''

Line 1569

<h2 class="rtoc-caption"><?php esc_html_e( 'Live Preview', 'rich-table-of-content' ); ?></h2>