reorder pages in chapter 12

diff --git a/_manual/12_adding-pre-existing-material/05_import-dialog.html b/_manual/12_adding-pre-existing-material/01_import-dialog.html
similarity index 100%
rename from _manual/12_adding-pre-existing-material/05_import-dialog.html
rename to _manual/12_adding-pre-existing-material/01_import-dialog.html

diff --git a/_manual/12_adding-pre-existing-material/01_importing-versus-embedding.html b/_manual/12_adding-pre-existing-material/02_importing-versus-embedding.html
similarity index 100%
rename from _manual/12_adding-pre-existing-material/01_importing-versus-embedding.html
rename to _manual/12_adding-pre-existing-material/02_importing-versus-embedding.html

diff --git a/_manual/12_adding-pre-existing-material/02_searching-and-importing-from-freesound.html b/_manual/12_adding-pre-existing-material/03_searching-and-importing-from-freesound.html
similarity index 100%
rename from _manual/12_adding-pre-existing-material/02_searching-and-importing-from-freesound.html
rename to _manual/12_adding-pre-existing-material/03_searching-and-importing-from-freesound.html

diff --git a/_manual/12_adding-pre-existing-material/03_searching-for-files-using-tags.html b/_manual/12_adding-pre-existing-material/04_searching-for-files-using-tags.html
similarity index 100%
rename from _manual/12_adding-pre-existing-material/03_searching-for-files-using-tags.html
rename to _manual/12_adding-pre-existing-material/04_searching-for-files-using-tags.html

diff --git a/_manual/12_adding-pre-existing-material/03_searching-for-files-using-tags/01_how-to-add-tags-to-a-file.html b/_manual/12_adding-pre-existing-material/04_searching-for-files-using-tags/01_how-to-add-tags-to-a-file.html
similarity index 100%
rename from _manual/12_adding-pre-existing-material/03_searching-for-files-using-tags/01_how-to-add-tags-to-a-file.html
rename to _manual/12_adding-pre-existing-material/04_searching-for-files-using-tags/01_how-to-add-tags-to-a-file.html

diff --git a/_manual/12_adding-pre-existing-material/03_searching-for-files-using-tags/02_searching-with-tags.html b/_manual/12_adding-pre-existing-material/04_searching-for-files-using-tags/02_searching-with-tags.html
similarity index 100%
rename from _manual/12_adding-pre-existing-material/03_searching-for-files-using-tags/02_searching-with-tags.html
rename to _manual/12_adding-pre-existing-material/04_searching-for-files-using-tags/02_searching-with-tags.html

diff --git a/_manual/12_adding-pre-existing-material/04_supported-file-formats.html b/_manual/12_adding-pre-existing-material/05_supported-file-formats.html
similarity index 100%
rename from _manual/12_adding-pre-existing-material/04_supported-file-formats.html
rename to _manual/12_adding-pre-existing-material/05_supported-file-formats.html