Improve template cache tag documentation

[Julian Bez]

For me it was not clear that the fragment name cannot be a variable. I just found out by wondering about errors and having a quick look into Django's code. It should be made more clear that the second argument will not be resolved even though all the others will be (even the cache time gets resolved).

"It takes at least two arguments: the cache timeout, in seconds, and the name to give the cache fragment. For example:"

should at least be something like

"It takes at least two arguments: the cache timeout, in seconds, and the name to give the cache fragment. The name will be taken as is, do not use a variable. For example:"

​https://docs.djangoproject.com/en/dev/topics/cache/#template-fragment-caching

[Florian Apolloner]

Shouldn't we instead add a new cache tag to our future library to get this tag in line with the other tags (like we did with url and ssi)?

[anonymous]

There's an open pull request at ​https://github.com/django/django/pull/153

[Julian Bez <web-spy@…>]

In [3c0877938f5eafc822d32b6c4f85e5a46b873390]:

Fixed #18110 -- Improve template cache tag documentation

[Tim Graham <timograham@…>]

In [84c3c9097d4a240ae2880ba272a207b96ddf7553]:

Merge pull request #153 from webjunkie/patch-1

Fixed #18110 -- Improve template cache tag documentation